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Sample records for 8-anilino-1-naphthalene sulfonate ans

  1. ANS complex of St John’s wort PR-10 protein with 28 copies in the asymmetric unit: a fiendish combination of pseudosymmetry with tetartohedral twinning

    SciTech Connect

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J.; Read, Randy J.; Jaskolski, Mariusz

    2015-04-01

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from H. perforatum, was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The asymmetric unit of the tetartohedrally twinned crystal contains 28 copies of the protein arranged in columns with noncrystallographic sevenfold translational symmetry and with additional pseudotetragonal rotational NCS. Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John’s wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packed as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.

  2. Unfolding and refolding of leucoagglutinin (PHA-L), an oligomeric lectin from kidney beans (Phaseolus vulgaris).

    PubMed

    Biswas, Shyamasri; Kayastha, Arvind M

    2004-09-01

    The unfolding and refolding of Phaseolus vulgaris Leucoagglutinin, a homotetrameric legume lectin, was studied at pH 2.5 and 7.2 using fluorescence, far- and near-UV circular dichroism (CD) spectroscopy, 8-anilino-1-naphthalene sulfonate (ANS) binding and FPLC techniques. This protein was found to refold even at pH 2.5 and also exhibited high refolding yield around 60% at pH 2.5 and 85% at pH 7.2. The refolding at pH 2.5 takes place with the formation of a dimeric intermediate. Although the hydrodynamic radius of the completely renatured protein and the dimer at pH 2.5 was found to be same, the ANS binding as well as far-UV CD spectra of the two were different. The denaturation kinetics at pH 2.5 followed single exponential pattern with the rate of denaturation being independent of protein concentration. The renaturation kinetics on the other hand was dependent on the protein concentration providing further evidence of an intermediate state during refolding. From these experiments the folding pathway of the protein at pH 2.5 was proposed. PMID:15342112

  3. ANS complex of St John’s wort PR-10 protein with 28 copies in the asymmetric unit: a fiendish combination of pseudosymmetry with tetartohedral twinning

    PubMed Central

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J.; Read, Randy J.; Jaskolski, Mariusz

    2015-01-01

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John’s wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packed as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them. PMID:25849394

  4. ANS complex of St John's wort PR-10 protein with 28 copies in the asymmetric unit: A fiendish combination of pseudosymmetry with tetartohedral twinning

    SciTech Connect

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J.; Read, Randy J.; Jaskolski, Mariusz

    2015-03-26

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John's wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packed as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.

  5. ANS complex of St John's wort PR-10 protein with 28 copies in the asymmetric unit: A fiendish combination of pseudosymmetry with tetartohedral twinning

    DOE PAGESBeta

    Sliwiak, Joanna; Dauter, Zbigniew; Kowiel, Marcin; McCoy, Airlie J.; Read, Randy J.; Jaskolski, Mariusz

    2015-03-26

    Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John's wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packedmore » as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.« less

  6. Thermodynamic analysis of ANS binding to partially unfolded α-lactalbumin: correlation of endothermic to exothermic changeover with formation of authentic molten globules.

    PubMed

    Kim, Ki Hyung; Yun, Soi; Mok, K H; Lee, E K

    2016-09-01

    A fluorescent reporter, 8-anilino-1-naphthalene sulfonic acid (ANS), can serve as a reference molecule for conformational transition of a protein because its aromatic carbons have strong affinity with hydrophobic cores of partially unfolded molten globules. Using a typical calcium-binding protein, bovine α-lactalbumin (BLA), as a model protein, we compared the ANS binding thermodynamics to the decalcified (10 mM EDTA treated) apo-BLA at two representative temperatures: 20 and 40 °C. This is because the authentic molten globule is known to form more heavily at an elevated temperature such as 40 °C. Isothermal titration calorimetry experiments revealed that the BLA-ANS interactions at both temperatures were entropy-driven, and the dissociation constants were similar on the order of 10(-4)  M, but there was a dramatic changeover in the binding thermodynamics from endothermic at 20 °C to exothermic at 40 °C. We believe that the higher subpopulation of authentic molten globules at 40 °C than 20 °C would be responsible for the results, which also indicate that weak binding is sufficient to alter the ANS binding mechanisms. We expect that the thermodynamic properties obtained from this study would serve as a useful reference for investigating the binding of other hydrophobic ligands such as oleic acid to apo-BLA, because oleic acid is known to have tumor-selective cytotoxicity when complexed with partially unfolded α-lactalbumin. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27060481

  7. Glucose-sensing proteins from mesophilic and thermophilic bacteria as new tools in diabetes monitoring

    NASA Astrophysics Data System (ADS)

    D'Auria, S.; Rossi, Mose; Lakowicz, Joseph R.

    2001-05-01

    We developed a new method of glucose sensing using inactive forms of glucose oxidase from Aspergillus niger and glucose dehydrogenase from the thermophilic microorganism Thermoplasma acidophilum. Glucose oxidase was rendered inactive by removal of the FAD cofactor. The resulting apo- glucose oxidase still binds glucose as observed from a decrease in its intrinsic tryptophan fluorescence. 8- Anilino-1-naphthalene sulfonic acid (ANS) was found to bind spontaneously to apo-glucose oxidase as seen from an enhancement of the ANS fluorescence. The steady state intensity of the bound ANS decreased 25% upon binding of glucose, and the mean lifetime of the bound ANS decreased about 40%. These spectral changes occurred with a midpoint from 10 to 20 mM glucose, which is comparable to the Ko of holo-glucose oxidase. These results suggest that apo- glucose oxidase can be used as a reversible non-consuming sensor for glucose.

  8. Pyrolysis Pathways of Sulfonated Polyethylene, an Alternative Carbon Fiber Precursor

    SciTech Connect

    Younker, Jarod M; Saito, Tomonori; Hunt, Marcus A; Beste, Ariana; Naskar, Amit K

    2013-01-01

    Sulfonated polyethylene is an emerging precursor for the production of carbon fibers. Pyrolysis of sulfonated polyethylene was characterized by thermogravimetric analysis (TGA). n-heptane-4-sulfonic acid (H4S) was selected as a model compound for the study of sulfonated polyethylene. Density functional theory and conventional transition state theory were used to determine the rate constants of pyrolysis for H4S from 300-1000 K. Multiple reaction channels from two different mechanisms were explored: 1) internal five-centered elimination (Ei 5) and 2) radical chain reaction. The pyrolysis of H4S was simulated with kinetic Monte Carlo (kMC) to obtain TGA plots that compared favorably to experiment. We observed that at tem- peratures < 550 K, the radical mechanism was dominant and yielded the trans-alkene, whereas cis-alkene was formed at higher temperatures from the internal elimination. The maximum rates of % mass loss became independent of initial OH radical concentration at 440-480 K. Experimentally, the maximum % mass loss occurred from 440-460 K (heating rate dependent). Activation energies derived from the kMC-simulated TGAs of H4S (26-29 kcal/mol) agreed with experiment for sulfonated polyethylene ( 31 kcal/mol). The simulations revealed that in this region, decomposition of radical HOSO2 became competitive to H abstraction by HOSO2, making OH the carrying radical for the reaction chain. The maximum rate of % mass loss for internal elimination was observed at temperatures > 600 K. Low-scale carbonization utilizes temperatures < 620 K; thus, internal elimination will not be competitive. Ei5 elimination has been studied for sulfoxides and sulfones, but this represents the first study of internal elimination in sulfonic acids. Nonlinear Arrhenius plots were found for all bimolecular reactions. The most significant nonlinear behavior was observed for reactions where the barrier was small. For reactions with low activation barriers, nonlinearity was traced to

  9. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., sulfonated aromatic (generic name). 721.950 Section 721.950 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... chemical substance identified generically as a sodium salt of an alkylated, sulfonated aromatic (PMN...

  10. Process for recovering 4,4 prime dihydroxydiphenyl sulfone from an isomer mixture

    SciTech Connect

    Zemlanicky, F.; Cooker, B.

    1991-03-19

    This patent describes a process for the recovery of 4,4{prime}-bisphenol sulfone from an isomer mixture comprising 4,4{prime}-bisphenol sulfone and 2,4{prime}-bisphenol sulfone. It comprises dissolving the isomer mixture in a basic aqueous solution comprising about one mole of base per mole of the mixture of 4,4{prime}-bisphenol sulfone and 2,4{prime}-bisphenol sulfone to form a basic isomer solution and adding acid to the isomer solution in an amount of from about 0.85 to 0.95 mole per mole of the 4,4{prime}-bisphenol sulfone wherein the acid is added in an amount sufficient to cause selective precipitation of crystals of 4,4{prime}-bisphenol sulfone yet in an amount less than sufficient to neutralize the isomer solution and removing the crystals of 4,4{prime}-bisphenol from the aqueous solution.

  11. 40 CFR 721.950 - Sodium salt of an alkylated, sulfonated aromatic (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sodium salt of an alkylated... Significant New Uses for Specific Chemical Substances § 721.950 Sodium salt of an alkylated, sulfonated... chemical substance identified generically as a sodium salt of an alkylated, sulfonated aromatic (PMN...

  12. A novel approach to the discovery of small molecule ligands of CDK2

    PubMed Central

    Martin, Mathew P.; Alam, Riazul; Betzi, Stephane; Ingles, Donna J.; Zhu, Jin-Yi

    2012-01-01

    In an attempt to identify novel small molecule ligands of CDK2 with potential as allosteric inhibitors, we devised a robust and cost-effective fluorescence-based high-throughput screening assay. The assay is based on the specific interaction of CDK2 with the extrinsic fluorophore 8-anilino-1-naphthalene sulfonate (ANS), which binds to a large allosteric pocket adjacent to the ATP site. Hit compounds which displace ANS directly or indirectly from CDK2 are readily classified as ATP site binders or allosteric ligands through the use of staurosporine, which blocks the ATP site without displacing ANS. Pilot screening of 1,453 compounds led to the discovery of 12 compounds with displacement activities (EC50 values) ranging from 6 to 44 μM, all of which were classified as ATP site-directed ligands. Four new Type I inhibitor scaffolds were confirmed by X-ray crystallography. While this small compound library contained only ATP-site directed ligands, the application of this assay to large compound libraries has the potential to reveal previously unrecognized chemical scaffolds suitable for structure-based design of CDK2 inhibitors with new mechanisms of action. PMID:22893598

  13. Deciphering aggregates, prefibrillar oligomers and protofibrils of cytochrome c.

    PubMed

    Amani, Samreen; Naeem, Aabgeena

    2014-08-01

    Aggregation of protein into insoluble intracellular complexes and inclusion bodies underlies the pathogenesis of human neurodegenerative diseases. Importance of cytochrome c (cyt c) arises from its involvement in apoptosis, sequence homology and for studying molecular evolution. A systemic investigation of polyethylene glycol (PEG) and trifluoroethanol (TFE) on the conformational stability of cyt c as a model hemeprotein was made using multi-methodological approach. Cyt c exists as molten globule (MG) at 60% PEG-400 and 40% TFE as confirmed by far-UV CD, attenuated total reflection Fourier transform infrared spectroscopy, Trp environment, 8-anilino-1-naphthalene-sulfonic acid (ANS) binding and blue shift in the soret band. Q-band splitting in MG states specifies conformational changes in the hydrophobic heme-binding pocket. Aggregates were detected at 90% PEG-400 and 50% TFE as confirmed by increase thioflavin T and ANS fluorescence and shift in Congo red absorbance. Detection of prefibrils and protofibrils at 90% PEG-400 and 50% TFE was possible after 72-h incubation. Single cell gel electrophoresis of prefibrils and protofibrils showed DNA damage confirming their toxicity and potential health hazards. Scanning electron microscopy and XRD analysis confirmed prefibrillar oligomers and protofibrils of cyt c. PMID:24729012

  14. Binding interaction of differently charged fluorescent probes with egg yolk phosphatidylcholine and the effect of β-cyclodextrin on the lipid-probe complexes: A fluorometric investigation

    NASA Astrophysics Data System (ADS)

    Kundu, Pronab; Ghosh, Saptarshi; Jana, Barnali; Chattopadhyay, Nitin

    2015-05-01

    Interaction of cationic phenosafranin (PSF), anionic 8-anilino-1-naphthalene sulfonate (ANS) and non-ionic nile red (NR) have been studied with the zwitterionic phospholipid, egg yolk L-α-phosphatidylcholine (EYPC). The study reveals discernible binding interactions of the three fluorescent probes with the EYPC lipid vesicle. Once the binding of the probes with the lipid is established, the effect of cyclic oligosaccharide, β-cyclodextrin (β-CD), on these lipid bound probes has been investigated. Different fluorometric techniques suggest that addition of β-CD to the probe-lipid complexes leads to the release of the probes from the lipid medium through the formation of probe-β-CD inclusion complexes. A competitive binding of the probes between β-cyclodextrin and the lipid is ascribed to be responsible for the effect. This provides an easy avenue for the removal of the probe molecules from the lipid environment. Extension of this work with drug molecules in cell membranes is expected to give rise to a strategy for the removal of adsorbed drugs from the cell membranes by the use of non-toxic β-cyclodextrin.

  15. BODIPY-Based Fluorescent Probes for Sensing Protein Surface-Hydrophobicity

    PubMed Central

    Dorh, Nethaniah; Zhu, Shilei; Dhungana, Kamal B.; Pati, Ranjit; Luo, Fen-Tair; Liu, Haiying; Tiwari, Ashutosh

    2015-01-01

    Mapping surface hydrophobic interactions in proteins is key to understanding molecular recognition, biological functions, and is central to many protein misfolding diseases. Herein, we report synthesis and application of new BODIPY-based hydrophobic sensors (HPsensors) that are stable and highly fluorescent for pH values ranging from 7.0 to 9.0. Surface hydrophobic measurements of proteins (BSA, apomyoglobin, and myoglobin) by these HPsensors display much stronger signal compared to 8-anilino-1-naphthalene sulfonic acid (ANS), a commonly used hydrophobic probe; HPsensors show a 10- to 60-fold increase in signal strength for the BSA protein with affinity in the nanomolar range. This suggests that these HPsensors can be used as a sensitive indicator of protein surface hydrophobicity. A first principle approach is used to identify the molecular level mechanism for the substantial increase in the fluorescence signal strength. Our results show that conformational change and increased molecular rigidity of the dye due to its hydrophobic interaction with protein lead to fluorescence enhancement. PMID:26679512

  16. Compact acid-induced state of Clitoria ternatea agglutinin retains its biological activity.

    PubMed

    Naeem, A; Saleemuddin, M; Khan, R H

    2009-10-01

    The effects of pH on Clitoria ternatea agglutinin (CTA) were studied by spectroscopy, size-exclusion chromatography, and by measuring carbohydrate specificity. At pH 2.6, CTA lacks well-defined tertiary structure, as seen by fluorescence and near-UV CD spectra. Far-UV CD spectra show retention of 50% native-like secondary structure. The mean residue ellipticity at 217 nm plotted against pH showed a transition around pH 4.0 with loss of secondary structure leading to the formation of an acid-unfolded state. This state is relatively less denatured than the state induced by 6 M guanidine hydrochloride. With a further decrease in pH, this unfolded state regains ~75% secondary structure at pH 1.2, leading to the formation of the A-state with native-like near-UV CD spectral features. Enhanced 8-anilino-1-naphthalene-sulfonate binding was observed in A-state, indicating a "molten-globule" like conformation with exposed hydrophobic residues. Acrylamide quenching data exhibit reduced accessibility of quencher to tryptophan, suggesting a compact conformation at low pH. Size-exclusion chromatography shows the presence of a compact intermediate with hydrodynamic size corresponding to a monomer. Thermal denaturation of the native state was cooperative single-step transition and of the A-state was non-cooperative two-step transition. A-State regains 72% of the carbohydrate-binding activity. PMID:19916921

  17. Cryoprotective mechanism of a small intrinsically disordered dehydrin protein

    PubMed Central

    Hughes, Stephanie; Graether, Steffen P

    2011-01-01

    Dehydration proteins (Dehydrins) are expressed during dehydration stress in plants and are thought to protect plant proteins and membranes from the loss of water during drought and at cold temperatures. Several different dehydrins have been shown to protect lactate dehydrogenase (LDH) from damage from being frozen and thawed. We show here that a 48 residue K2 dehydrin from Vitis riparia protects LDH more effectively than bovine serum albumin, a protein with known cryoprotective function. Light scattering and 8-anilino-1-naphthalene sulfonate fluorescence experiments show that dehydrins prevent aggregation and unfolding of the enzyme. The cryoprotective effects of LDH are reduced by the addition of salt, suggesting that the positively charged K-segments are attracted to a negatively charged surface but this does not result in binding. Overall K2 is an intrinsically disordered protein; nuclear magnetic resonance relaxation experiments indicate that the two-terminal, Lys-rich K-segments show a weak propensity for α-helicity and are flexible, and that the central, polar rich phi-segment has no secondary structure preference and is highly flexible. We propose that the phi-segments in dehydrins are important for maintaining the disordered structure so that the protein can act as a molecular shield to prevent partially denatured proteins from interacting with one another, whereas the K-segments may help to localize the dehydrin near the enzyme surface. PMID:21031484

  18. Thyroxine 5'-monodeiodinase activity in hepatocytes of rainbow trout, Salmo gairdneri: distribution, effects of starvation, and exogenous inhibitors.

    PubMed

    Shields, C A; Eales, J G

    1986-09-01

    L-Thyroxine (T4) 5'-monodeiodinase activity (MDA) of hepatocyte cell fractions of rainbow trout was evaluated by 125I- generation following incubation with [125I-3' or 125I-5']T4 at 12 degrees. Produced in approximately equal proportions, 3,5,[125I-3'] triiodo-L-thyronine and 125I- were the sole labeled products detected by gel permeation on G-25 Sephadex columns, confirming restriction of T4 deiodination in trout to removal of a single outer-ring iodine atom. T3 underwent no significant outer-ring deiodination. MDA activity, located mainly in the microsome fraction, was optimal at a pH of approximately 7.0 and was enhanced by dithiothreitol but not by reduced glutathione. Azide, thiocyanate, thiourea, and KCl exerted no significant influence on MDA, but MDA was inhibited by: 8-anilino-1-naphthalene sulfonic acid greater than N-ethyl maleimide greater than propylthiouracil greater than sodium salicylate greater than KI. Starvation for 2 weeks depressed MDA to 46% of the level of trout fed 1% of body wt once per day. This was due to a decreased Vmax of MDA. In conclusion, trout hepatic microsomal MDA is acutely and chronically susceptible to both exogenous and endogenous factors; as an enzyme responsible for extrathyroidal T3 generation, it may exert a key role in regulating peripheral thyroidal status under both natural and experimental conditions. PMID:3557058

  19. Cryoprotective mechanism of a small intrinsically disordered dehydrin protein.

    PubMed

    Hughes, Stephanie; Graether, Steffen P

    2011-01-01

    Dehydration proteins (Dehydrins) are expressed during dehydration stress in plants and are thought to protect plant proteins and membranes from the loss of water during drought and at cold temperatures. Several different dehydrins have been shown to protect lactate dehydrogenase (LDH) from damage from being frozen and thawed. We show here that a 48 residue K₂ dehydrin from Vitis riparia protects LDH more effectively than bovine serum albumin, a protein with known cryoprotective function. Light scattering and 8-anilino-1-naphthalene sulfonate fluorescence experiments show that dehydrins prevent aggregation and unfolding of the enzyme. The cryoprotective effects of LDH are reduced by the addition of salt, suggesting that the positively charged K-segments are attracted to a negatively charged surface but this does not result in binding. Overall K₂ is an intrinsically disordered protein; nuclear magnetic resonance relaxation experiments indicate that the two-terminal, Lys-rich K-segments show a weak propensity for α-helicity and are flexible, and that the central, polar rich phi-segment has no secondary structure preference and is highly flexible. We propose that the phi-segments in dehydrins are important for maintaining the disordered structure so that the protein can act as a molecular shield to prevent partially denatured proteins from interacting with one another, whereas the K-segments may help to localize the dehydrin near the enzyme surface. PMID:21031484

  20. A fluorescence study on the interaction of telmisartan in triblock polymers pluronic P123 and F127

    NASA Astrophysics Data System (ADS)

    Mohanty, Maneesha Esther; Rao, Vaidya Jayathirtha; Mishra, Ashok Kumar

    2014-03-01

    Telmisartan is a poorly soluble drug used in treatment of hypertension. There is a recent interest to use pluronic for improving the solubility and bioavailability of these drugs. In this study the interaction of telmisartan with P123 and F127 has been carried out using steady state and time dependent fluorescence study. Quenching of telmisartan fluorescence by potassium iodide is controlled by interactions arising from collisions and complex formation. A comparison of the fluorescence of telmisartan in pluronics with the well understood fluorescence of 8-anilino-1-naphthalene-sulfonic acid, a known fluorescent molecular probe, indicates that telmisartan is generally present in a relatively polar microenvironment with restricted diffusive motion.

  1. Coupling hydrogen separation with butanone hydrogenation in an electrochemical hydrogen pump with sulfonated poly (phthalazinone ether sulfone ketone) membrane

    NASA Astrophysics Data System (ADS)

    Huang, Shiqi; Wang, Tao; Wu, Xuemei; Xiao, Wu; Yu, Miao; Chen, Wei; Zhang, Fengxiang; He, Gaohong

    2016-09-01

    This work reports the novel work of coupling H2/CO2 separation with biomass-derived butanone hydrogenation in non-fluorinated sulfonated poly (phthalazinone ether sulfone ketone) (SPPESK) electrochemical hydrogen pump (EHP) reactor. Due to higher resistance to swelling, SPPESK-based EHP reactor exhibits more excellent reaction rate in elevated temperature (60 °C) and higher butanone concentration (2 M) as 270, 260 nmol cm-2 s-1, respectively, higher than 240, 200 nmol cm-2 s-1of Nafion-based EHP reactors. Also, the SPPESK-based EHP reactor remains 90% of initial hydrogenation rate after 4 batches, better than that of Nafion-based EHP reactors, which is only 62%. The energy efficiency of EHP separator reaches 40% under H2/CO2 mixture feed mode, and electricity of about 0.3 kWh is consumed per Nm3 H2 product, being superior to energy consumption compared with alternative processes like PSA and electrolysis of water. In addition, SPPESK-based EHP exhibits better hydrogenation stability due to lower CO2 permeation than Nafion. With increasing CO2 content in H2 feed, hydrogenation rate almost keeps constant at around 210 nmol cm-2 s-1 in SPPESK-based EHP reactor while decreases fast to 50 nmol cm-2 s-1 in Nafion/PTFE-based EHP reactor. These results show integration of gas separation with hydrogenation reactor is feasible in SPPESK-based EHP reactor.

  2. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  3. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  4. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  5. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  6. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  7. Sodium Polystyrene Sulfonate

    MedlinePlus

    ... comes as a suspension and as an oral powder for suspension to take by mouth. The suspension ... evenly.If you are taking sodium polystyrene sulfonate powder by mouth, mix the powder with 20 to ...

  8. Influence of group composition of sulfonic acids on properties of sulfonate additives

    SciTech Connect

    Katrenko, T.I.; Bessonova, R.N.; Kuznetsova, M.G.; Potolovskii, L.A.

    1983-05-01

    Three types of sulfonic acids are formed in sulfonation of petroleum oils-- oil-soluble, oil-insoluble, and water-soluble. This study investigates the influence of the different acids on neutral calcium sulfonates. Samples are recovered from As-14 oil. Oil-insoluble synthesis failed. Water-soluble acid did synthesize with a mix of oil- and water-soluble sulfonates. Neutral calcium sulfonates synthesized from oil-soluble had good properties, from oil-insoluble, bad properties. Oil-insoluble sulfonate also has an inverse effect on cleanup, and it interferes with carbonation. These findings will help with improvements in the sulfonate additive manufacturing process.

  9. Drilling fluids based on a mixture of a sulfonated thermoplastic polymer and a sulfonated elastomeric polymer

    SciTech Connect

    Turner, S.R.; Lundberg, R.D.; Peiffer, D.G.; Thaler, W.A.; Walker, T.O.

    1984-01-10

    The present invention relates to mixtures of sulfonated thermoplastic polymers and sulfonated elastomeric polymers which function as viscosification agents when added to oil-based drilling muds which are the fluids used to maintain pressure, cool drill bits, and lift cuttings from the holes in the drilling operation for oil and gas wells. The sulfonated thermoplastic and elastomeric polymers both have about 5 to about 200 meq. of sulfonate groups per 100 grams of the sulfonated thermoplastic or elastomeric polymers, wherein the sulfonated groups are neutralized with a metallic cation or an amine or ammonium counterion. A polar cosolvent can optionally be added to the mixture of oil drilling mud and sulfonated thermoplastic and elastomeric polymers, wherein the polar cosolvent increases the solubility of the sulfonated thermoplastic and elastomeric polymer in the oil drilling mud by decreasing the strong ionic interactions between the sulfonate groups of the sulfonated polymers.

  10. Aldicarb sulfone

    Integrated Risk Information System (IRIS)

    Aldicarb sulfone ; CASRN 1646 - 88 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  11. Effect of sodium dodecylbenzene sulfonate on subtilisin Carlsberg proteolysis of an immobilized ovalbumin film.

    PubMed

    Foose, Ladan L; Blanch, Harvey W; Radke, C J

    2009-03-01

    Enzymatic degradation of immobilized ovalbumin multilayer films by subtilisin Carlsberg was investigated using in situ ellipsometry. Changes in the substrate cleavage rate in the presence of an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), were assessed. Exposure of the protein film to SDBS prior to introduction of the enzyme increased the measured proteolysis rate threefold. Surfactant increased the measured film thickness, absorbing into the protein film and causing swelling. Surfactant-induced film swelling was reversible upon aqueous rinsing. Nevertheless, exposure of enzyme to the surfactant-rinsed film increased the proteolysis rate, most likely due to irreversible conformational changes induced in the substrate film by the surfactant. Simultaneous addition of SDBS with enzyme after the initial surfactant exposure did not produce additional protein-removal benefit. PMID:18985613

  12. Preparation of a sulfonated carbonaceous material from lignosulfonate and its usefulness as an esterification catalyst.

    PubMed

    Lee, Duckhee

    2013-01-01

    Sulfonated carbonaceous material useful as a solid acid catalyst was prepared from lignosulfonate, a waste of the paper-making industry sulfite pulping process, and characterized by 13C-NMR, FT-IR, TGA, SEM and elemental analysis, etc. The sulfonic acid group density and total density of all acid groups in the sulfonated carbonaceous material was determined by titration to be 1.24 mmol/g and 5.90 mmol/g, respectively. Its catalytic activity in the esterification of cyclohexanecarboxylic acid with anhydrous ethanol was shown to be comparable to that of the ionic exchange resin Amberlyst-15, when they were used in the same amount. In the meantime, the sulfonic acid group was found to be leached out by 26%-29% after it was exposed to hot water (95 °C) for 5 h. The catalytic usefulness of the prepared carbonaceous material was investigated by performing esterifications. PMID:23846757

  13. Development of coated tubes RIA for serum T3 (tri-iodothyronine) for production scale.

    PubMed

    Karir, T; Samuel, G; Sivaprasad, N; Meera, V; Samuel, G; Meera, V; Pillai, M R A

    2005-01-01

    A coating procedure that could provide immobilization of antibodies, with increased binding capacity, that is cost effective, simple, robust, and appropriate for production scale application, is described. This coating approach of T3 antibodies to the polystyrene tubes has been systematically investigated to determine its utility for the development of coated tube Radioimmunoassay (RIA) for T3 in human serum. Further, the results obtained by the developed coating procedure are found to be comparable with those obtained by the "gold standard," the liquid phase RIA for T3. The coating procedure is completed in three major steps, each step involving an overnight incubation. The normal rabbit gamma-globulins are physically adsorbed onto the polystyrene tubes and incubated. After washing, a second antibody (goat anti-rabbit antiserum) is added and incubated. To this antigen specific antibody is added (T3 antibody produced in rabbit) and further incubated. Finally, the non-specific sites on the tubes are saturated by the blocking solution. The concentration of normal rabbit globulin, titers of second antibody and T3 antibody, and time required for coating are optimized to arrive at a suitable coating protocol. The coated tubes were evaluated for precision, reproducibility, and stability. Various parameters such as total reaction volume, incubation time and temperature, total number and volume of washings, concentration of 8-anilino-1-naphthalene sulfonic acid (ANS), and quantity of tracer per tube are optimized to arrive at a suitable standard curve. The optimized assay is validated for the quality control parameters such as intra- and inter-assay variations, recovery, and parallelism. The developed coated tubes assay had an assay range of 0.3-4.8 ng/mL with a sensitivity of 0.3 ng/mL at 90% B/B0. Batch to batch variation in coating was < 10%. The coated tubes were stable up to 1 year, which is adequate for production scale. PMID:15754806

  14. Insights on Structural Characteristics and Ligand Binding Mechanisms of CDK2

    PubMed Central

    Li, Yan; Zhang, Jingxiao; Gao, Weimin; Zhang, Lilei; Pan, Yanqiu; Zhang, Shuwei; Wang, Yonghua

    2015-01-01

    Cyclin-dependent kinase 2 (CDK2) is a crucial regulator of the eukaryotic cell cycle. However it is well established that monomeric CDK2 lacks regulatory activity, which needs to be aroused by its positive regulators, cyclins E and A, or be phosphorylated on the catalytic segment. Interestingly, these activation steps bring some dynamic changes on the 3D-structure of the kinase, especially the activation segment. Until now, in the monomeric CDK2 structure, three binding sites have been reported, including the adenosine triphosphate (ATP) binding site (Site I) and two non-competitive binding sites (Site II and III). In addition, when the kinase is subjected to the cyclin binding process, the resulting structural changes give rise to a variation of the ATP binding site, thus generating an allosteric binding site (Site IV). All the four sites are demonstrated as being targeted by corresponding inhibitors, as is illustrated by the allosteric binding one which is targeted by inhibitor ANS (fluorophore 8-anilino-1-naphthalene sulfonate). In the present work, the binding mechanisms and their fluctuations during the activation process attract our attention. Therefore, we carry out corresponding studies on the structural characterization of CDK2, which are expected to facilitate the understanding of the molecular mechanisms of kinase proteins. Besides, the binding mechanisms of CDK2 with its relevant inhibitors, as well as the changes of binding mechanisms following conformational variations of CDK2, are summarized and compared. The summary of the conformational characteristics and ligand binding mechanisms of CDK2 in the present work will improve our understanding of the molecular mechanisms regulating the bioactivities of CDK2. PMID:25918937

  15. Likelihood-based molecular-replacement solution for a highly pathological crystal with tetartohedral twinning and sevenfold translational noncrystallographic symmetry

    SciTech Connect

    Sliwiak, Joanna; Dauter, Zbigniew; McCoy, Airlie J.; Read, Randy J.

    2014-02-01

    With the implementation of a molecular-replacement likelihood target that accounts for translational noncrystallographic symmetry, it became possible to solve the crystal structure of a protein with seven tetrameric assemblies arrayed translationally along the c axis. The new algorithm found 56 protein molecules in reduced symmetry (P1), which was used to resolve space-group ambiguity caused by severe twinning. Translational noncrystallographic symmetry (tNCS) is a pathology of protein crystals in which multiple copies of a molecule or assembly are found in similar orientations. Structure solution is problematic because this breaks the assumptions used in current likelihood-based methods. To cope with such cases, new likelihood approaches have been developed and implemented in Phaser to account for the statistical effects of tNCS in molecular replacement. Using these new approaches, it was possible to solve the crystal structure of a protein exhibiting an extreme form of this pathology with seven tetrameric assemblies arrayed along the c axis. To resolve space-group ambiguities caused by tetartohedral twinning, the structure was initially solved by placing 56 copies of the monomer in space group P1 and using the symmetry of the solution to define the true space group, C2. The resulting structure of Hyp-1, a pathogenesis-related class 10 (PR-10) protein from the medicinal herb St John’s wort, reveals the binding modes of the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS), providing insight into the function of the protein in binding or storing hydrophobic ligands.

  16. Conformational alterations induced by novel green 16-E2-16 gemini surfactant in xanthine oxidase: Biophysical insights from tensiometry, spectroscopy, microscopy and molecular modeling.

    PubMed

    Akram, Mohd; Bhat, Imtiyaz Ahmad; Bhat, Waseem Feeroze; Kabir-ud-Din

    2015-11-01

    Herein we report the interaction of a biodegradable gemini surfactant, ethane-1,2-diyl bis(N,N-dimethyl-N-hexadecylammoniumacetoxy) dichloride (16-E2-16) with bovine milk xanthine oxidase (XO), employing tensiometry, fluorescence spectroscopy, UV spectroscopy, far-UV circular dichroism spectroscopy (CD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and computational molecular modeling. Surface tension results depict substantial changes in the micellar as well as interfacial parameters (CMC, ΠCMC, γCMC, Γmax, Amin, ΔGmic° and ΔGads°) of 16-E2-16 gemini surfactant upon XO combination, deciphering the interaction of XO with the gemini surfactant. Fluorescence measurements reveal that 16-E2-16 gemini surfactant causes quenching in the xanthine oxidase (XO) fluorescence spectra via static procedure and the values of various evaluated binding parameters (KSV, Kb, kq, ΔGb° and n) describe that 16-E2-16 effectively binds to XO. Three dimensional fluorescence, 8-anilino-1-naphthalene sulfonic acid (ANS) binding, F1F3 ratio, UV, CD, FTIR, SEM and TEM results delineate changes in the secondary structure of xanthine oxidase. Molecular docking results provide complement to the steady-state fluorescence findings and support the view that quenching occurs due to non-polar environment experienced by aromatic residues of the enzyme. The results of this study can help scientists to tune the conformation of an enzyme (XO) with biocompatible amphiphilic microstructures, which will help to unfold further understanding in the treatment modes of various diseases like gout, hyperuricemia, liver and brain necrosis. PMID:26057098

  17. Fate of perfluorinated carboxylates and sulfonates during snowmelt within an urban watershed.

    PubMed

    Meyer, Torsten; De Silva, Amila O; Spencer, Christine; Wania, Frank

    2011-10-01

    The transport dynamics of perfluorinated carboxylic acids and sulfonates during snowmelt in the highly urbanized Highland Creek watershed in Toronto, Canada was investigated by analyzing river water, bulk snow, and groundwater, sampled in February and March 2010, by means of liquid chromatography-tandem mass spectrometry. Perfluorohexanoate, perfluorooctanoate, and perfluorooctane sulfonate were dominant in river water, with concentrations of 4.0-14 ng·L(-1), 2.2-7.9 ng·L(-1), and 2.1-6.5 ng·L(-1), respectively. Relatively high levels of perfluorohexanoate may be related to the recent partial replacement in various consumer products of perfluorooctyl substances with shorter-chained perfluorinated compounds (PFCs). Highest PFC concentrations were found within the more urbanized part of the drainage area, suggestive of residential, industrial, and/or traffic-related sources. The riverine flux of PFCs increased during the snowmelt period, but only approximately one-fifth of the increased flux can be attributed to PFCs present in the snowpack, mostly because concentration in snow are generally quite low compared to those in river water. The remainder of the increased flux must be due to the mobilization of PFCs by the high flow conditions prevalent during snowmelt. Run-off behavior was clearly dependent on perfluoroalkyl chain length: Dilution with relatively clean snowmelt water caused a drop in the river water concentrations of short-chain PFCs at high flow during early melting. This prevented an early concentration peak of those water-soluble PFCs within the stream, as could have been expected in response to their early release from a melting snowpack. Instead, concentrations of particle-associated long-chain PFCs in creek water peaked early in the melt, presumably because high flow mobilized contaminated particles from impervious surfaces in the more urbanized areas of the watershed. The ability to enter the subsurface and deeper groundwater aquifers increased

  18. Sodium Polystyrene Sulfonate

    MedlinePlus

    ... allergic to sodium polystyrene sulfonate, other polystyrene sulfonate resins, any other medications, or any of the ingredients ... salt substitutes containing potassium or foods that are high in potassium.

  19. Biodegradation of linear alkylbenzene sulfonate in commercial laundry wastewater by an anaerobic fluidized bed reactor.

    PubMed

    Braga, Juliana K; Motteran, Fabrício; Macedo, Thaís Z; Sakamoto, Isabel K; Delforno, Tiago P; Okada, Dagoberto Y; Silva, Edson L; Varesche, Maria Bernadete A

    2015-01-01

    The biodegradation of linear alkylbenzene sulfonate (LAS) from commercial laundry wastewater was evaluated in an anaerobic fluidized bed reactor (FBR) fed with synthetic substrate (598 mg L(-1) to 723 mg L(-1) of organic matter) supplemented with 9.5±3.1 mg L(-1) to 27.9±9.6 mg L(-1) of LAS. The average chemical oxygen demand (COD) removal efficiency was 89% and the biodegradation of LAS was 57% during the 489 days of anaerobic FBR. Higher levels of volatile fatty acids (VFA) were observed in the effluent at the stage with the best LAS removal performance. Increasing the surfactant concentration did not increase the VFA production in the effluent. The predominant VFAs after the addition of LAS were as follows: isovaleric acid and valeric acid, followed by propionic acid, caproic acid and formic acid. The similarities of 64% and 45% to Archaea and Bacteria domains were observed in the samples taken in the operating period of anaerobic FBR fed with 23.6±10 mg L(-1) and 27.9±10 mg L(-1) of LAS. During the operation stages in the reactor, Gemmatimonas, Desulfobulbus and Zoogloea were determined as the most abundant genera related to surfactant degradation using 454-Pyrosequencing. PMID:26061208

  20. Improvement of the chromatographic separation performance of an imidazolium ionic liquid functionalized silica column by in situ anion-exchange with dodecyl sulfonate and dodecylbenzene sulfonate anions.

    PubMed

    Sun, Min; Feng, Juanjuan; Chen, Wenjie; Li, Leilei; Duan, Huimin; Luo, Chuannan

    2014-06-01

    The anionic part of ionic liquids can provide additional interactions during chromatographic separations. In this work, the chromatographic separation performance of a silica column functionalized with 1-propyl-3-methylimidazolium chloride ionic liquid was improved by in situ anion-exchange from chloride anions to dodecyl sulfonate anions and dodecylbenzene sulfonate anions. The separation performances of these ionic liquid functionalized phases were investigated and compared with each other using polycyclic aromatic hydrocarbons, phthalates, parabens, and phenols as model compounds. Results indicated that the new columns presented a better chromatographic separation than the original one. This was ascribed retention mechanism from organic anions. The introduction of dodecyl sulfonate anions increased the hydrophobicity of stationary phase. Furthermore, the phenyl groups of dodecylbenzene sulfonate anions could provide an enhanced selectivity to aromatic compounds such as polycyclic aromatic hydrocarbons by π-π interactions. Analysis repeatability of the new columns was satisfactory (RSD of retention time, 0.10-0.40%; RSD of peak area, 0.66-0.84%). PMID:24616155

  1. Distillate fuels containing an amine salt of a sulfonic acid and a low volatility carrier fluid (PNE-554)

    SciTech Connect

    Ashcraft, T.L.; Schilowitz, A.M.; Talley, L.D.; Berlowitz, P.J.

    1993-06-01

    A distillate fuel composition is described comprising a major amount of gasoline and a minor synergistic amount of an additive combination of (a) an amine salt of a sulfonic acid wherein the amine moiety is a monoamine, a polyamine, a monoamine or a polyamine containing ether linkages, or mixtures thereof, said amine moiety containing from 2 to 100 carbon atoms and from 1 to 3 nitrogen atoms, and the sulfonic acid moiety is an alkyl benzyl sulfonic acid in which the alkyl group contains from 20 to 50 carbon atoms, and (b) a carrier fluid that is mineral oil base stock, a polyol ester, and mixtures thereof, wherein less than 10 volume % of the carrier fluid in vaporized at a temperature of 125 C., provided that the amount of component (a) in the fuel composition is from about 40 to about 1500 ppm and the amount of component (b) is from about 0.1 to about 10 times the amount of component (a).

  2. Constructing proton-conductive highways within an ionomer membrane by embedding sulfonated polymer brush modified graphene oxide

    NASA Astrophysics Data System (ADS)

    Zhao, Liping; Li, Yifan; Zhang, Haoqin; Wu, Wenjia; Liu, Jindun; Wang, Jingtao

    2015-07-01

    Sulfonated polymer brush modified graphene oxide (SP-GO) fillers with controllable brush length are synthesized via the facile distillation-precipitation polymerization, and then incorporated into sulfonated poly(ether ether ketone) (SPEEK) matrix to fabricate composite membranes. The influences of SP-GO upon the microstructures, including thermal and mechanical properties, water uptake/swelling, proton conduction, H2 permeability and single PEMFC performances of composite membranes are intensively investigated. It is found that the SP-GO fillers are uniformly dispersed and tend to lie perpendicularly to the cross-section surface of the whole membrane, which allow SP-GO fillers creating inter-connected and broad ionic pathways through the sulfonic acid groups in polymer brushes. Meanwhile, the SP-GO fillers connect the ionic clusters in SPEEK matrix via interfacial interactions. In such a way, proton-transfer highways are constructed along the SPEEK/SP-GO interface, which lower the proton transfer activation energy and enhance the proton conductivities of the composite membranes under both hydrated and anhydrous conditions. Furthermore, elevating the brush length on SP-GO could further enhance the proton conductivity. Compared to SPEEK control membrane, a 95.5% increase in hydrated conductivity, an 178% increase in anhydrous conductivity and a 37% increase in maximum power density are obtained for the optimal composite membrane.

  3. Decline in perfluorooctane sulfonate and perfluorooctanoate serum concentrations in an Australian population from 2002 to 2011

    PubMed Central

    Toms, L.-M.L.; Thompson, J.; Rotander, A.; Hobson, P.; Calafat, A.M.; Kato, K.; Ye, X.; Broomhall, S.; Harden, F.; Mueller, J.F.

    2016-01-01

    Some perfluoroalkyl and polyfluoroalkyl substances (PFASs) have become widespread pollutants detected in human and wildlife samples worldwide. The main objective of this study was to assess temporal trends of PFAS concentrations in human blood in Australia over the last decade (2002–2011), taking into consideration age and sex trends. Pooled human sera from 2002/03 (n = 26); 2008/09 (n = 24) and 2010/11 (n = 24) from South East Queensland, Australia were obtained from de-identified surplus pathology samples and compared with samples collected previously from 2006/07 (n = 84). A total of 9775 samples in 158 pools were available for an assessment of PFASs. Stratification criteria included sex and age: <16 years (2002/03 only); 0–4 (2006/07, 2008/09, 2010/11); 5–15 (2006/07, 2008/09, 2010/11); 16–30; 31–45; 46–60; and >60 years (all collection periods). Sera were analyzed using on-line solid-phase extraction coupled to high-performance liquid chromatography–isotope dilution-tandem mass spectrometry. Perfluorooctane sulfonate (PFOS) was detected in the highest concentrations ranging from 5.3–19.2 ng/ml (2008/09) to 4.4–17.4 ng/ml (2010/11). Perfluorooctanoate (PFOA) was detected in the next highest concentration ranging from 2.8–7.3 ng/ml (2008/09) to 3.1–6.5 ng/ml (2010/11). All other measured PFASs were detected at concentrations <1 ng/ml with the exception of perfluorohexane sulfonate which ranged from 1.2–5.7 ng/ml (08/09) and 1.4–5.4 ng/ml (10/11). The mean concentrations of both PFOS and PFOA in the 2010/11 period compared to 2002/03 were lower for all adult age groups by 56%. For 5–15 year olds, the decrease was 66% (PFOS) and 63% (PFOA) from 2002/03 to 2010/11. For 0–4 year olds the decrease from 2006/07 (when data were first available for this age group) was 50% (PFOS) and 22% (PFOA). This study provides strong evidence for decreasing serum PFOS and PFOA concentrations in an Australian population from 2002 through 2011. Age trends

  4. An Ethylmethane Sulfonate Mutant Resource in Pre-Green Revolution Hexaploid Wheat.

    PubMed

    Dhaliwal, Amandeep K; Mohan, Amita; Sidhu, Gaganjot; Maqbool, Rizwana; Gill, Kulvinder S

    2015-01-01

    Mutagenesis is a powerful tool used for studying gene function as well as for crop improvement. It is regaining popularity because of the development of effective and cost efficient methods for high-throughput mutation detection. Selection for semi-dwarf phenotype during green revolution has reduced genetic diversity including that for agronomically desirable traits. Most of the available mutant populations in wheat (Triticum aestivum L.) were developed in post-green revolution cultivars. Besides the identification and isolation of agronomically important alleles in the mutant population of pre-green revolution cultivar, this population can be a vital resource for expanding the genetic diversity for wheat breeding. Here we report an Ethylmethane Sulfonate (EMS) generated mutant population consisting of 4,180 unique mutant plants in a pre-green revolution spring wheat cultivar 'Indian'. Released in early 1900s, 'Indian' is devoid of any known height-reducing mutations. Unique mutations were captured by proceeding with single M2 seed from each of the 4,180 M1 plants. Mutants for various phenotypic traits were identified by detailed phenotyping for altered morphological and agronomic traits on M2 plants in the greenhouse and M3 plants in the field. Of the 86 identified mutants, 75 (87%) were phenotypically stable at the M4 generation. Among the observed phenotypes, variation in plant height was the most frequent followed by the leaf morphology. Several mutant phenotypes including looped peduncle, crooked plant morphology, 'gritty' coleoptiles, looped lower internodes, and burnt leaf tips are not reported in other plant species. Considering the extent and diversity of the observed mutant phenotypes, this population appears to be a useful resource for the forward and reverse genetic studies. This resource is available to the scientific community. PMID:26678261

  5. An Ethylmethane Sulfonate Mutant Resource in Pre-Green Revolution Hexaploid Wheat

    PubMed Central

    Dhaliwal, Amandeep K.; Mohan, Amita; Sidhu, Gaganjot; Maqbool, Rizwana; Gill, Kulvinder S.

    2015-01-01

    Mutagenesis is a powerful tool used for studying gene function as well as for crop improvement. It is regaining popularity because of the development of effective and cost efficient methods for high-throughput mutation detection. Selection for semi-dwarf phenotype during green revolution has reduced genetic diversity including that for agronomically desirable traits. Most of the available mutant populations in wheat (Triticum aestivum L.) were developed in post-green revolution cultivars. Besides the identification and isolation of agronomically important alleles in the mutant population of pre-green revolution cultivar, this population can be a vital resource for expanding the genetic diversity for wheat breeding. Here we report an Ethylmethane Sulfonate (EMS) generated mutant population consisting of 4,180 unique mutant plants in a pre-green revolution spring wheat cultivar ‘Indian’. Released in early 1900s, ‘Indian’ is devoid of any known height-reducing mutations. Unique mutations were captured by proceeding with single M2 seed from each of the 4,180 M1 plants. Mutants for various phenotypic traits were identified by detailed phenotyping for altered morphological and agronomic traits on M2 plants in the greenhouse and M3 plants in the field. Of the 86 identified mutants, 75 (87%) were phenotypically stable at the M4 generation. Among the observed phenotypes, variation in plant height was the most frequent followed by the leaf morphology. Several mutant phenotypes including looped peduncle, crooked plant morphology, ‘gritty’ coleoptiles, looped lower internodes, and burnt leaf tips are not reported in other plant species. Considering the extent and diversity of the observed mutant phenotypes, this population appears to be a useful resource for the forward and reverse genetic studies. This resource is available to the scientific community. PMID:26678261

  6. Computational Studies of Gramicidin Permeation: An Entryway Sulfonate Enhances Cation Occupancy at Entry Sites

    PubMed Central

    Mustafa, Morad; Henderson, Douglas J.; Busath, David D.

    2009-01-01

    The impact on the cation-transport free-energy profile of replacing the C-terminal ethanolamine in the gramicidin A channel with a taurine residue is studied using molecular dynamics simulations of gramicidin A (1JNO) embedded in a lipid bilayer (DMPC) with 1 mol/kg NaCl saline solution. The potential of mean force for ion transport is obtained by umbrella sampling. The presence of a negatively charged sulfonate group at the entrance of the gramicidin channel affects the depth and the location of the binding sites, producing a strong attraction for the cations in the bulk. The potential of mean force by the sulfonate acting directly through electrostatics and van der Waals interactions on the test ion is highly modulated by indirect effects (i.e., sulfonate effects on other components of the system that, in turn, affect the ion free-energy profile in the channel). Because the “entry” sites are located symmetrically at both entry and exit of the channel, the deeper free-energy wells should inhibit exit. Given that the channel has increased conductance experimentally, the simulation results suggest that the channel conductance is normally entry limited. PMID:19361485

  7. A fluorescence study on the interaction of telmisartan in triblock polymers pluronic P123 and F127.

    PubMed

    Mohanty, Maneesha Esther; Rao, Vaidya Jayathirtha; Mishra, Ashok Kumar

    2014-01-01

    Telmisartan is a poorly soluble drug used in treatment of hypertension. There is a recent interest to use pluronic for improving the solubility and bioavailability of these drugs. In this study the interaction of telmisartan with P123 and F127 has been carried out using steady state and time dependent fluorescence study. Quenching of telmisartan fluorescence by potassium iodide is controlled by interactions arising from collisions and complex formation. A comparison of the fluorescence of telmisartan in pluronics with the well understood fluorescence of 8-anilino-1-naphthalene-sulfonic acid, a known fluorescent molecular probe, indicates that telmisartan is generally present in a relatively polar microenvironment with restricted diffusive motion. PMID:24263130

  8. An exploratory NMR nutri-metabonomic investigation reveals dimethyl sulfone as a dietary biomarker for onion intake.

    PubMed

    Winning, Hanne; Roldán-Marín, Eduvigis; Dragsted, Lars O; Viereck, Nanna; Poulsen, Morten; Sánchez-Moreno, Concepción; Cano, M Pilar; Engelsen, Søren B

    2009-11-01

    The metabolome following intake of onion by-products is evaluated. Thirty-two rats were fed a diet containing an onion by-product or one of the two derived onion by-product fractions: an ethanol extract and the residue. A 24 hour urine sample was analyzed using (1)H NMR spectroscopy in order to investigate the effects of onion intake on the rat metabolism. Application of interval extended canonical variates analysis (ECVA) proved to be able to distinguish between the metabolomic profiles from rats consuming normal feed and rats fed with an onion diet. Two dietary biomarkers for onion intake were identified as dimethyl sulfone and 3-hydroxyphenylacetic acid. The same two dietary biomarkers were subsequently revealed by interval partial least squares regression (PLS) to be perfect quantitative markers for onion intake. The best PLS calibration model yielded a root mean square error of cross-validation (RMSECV) of 0.97% (w/w) with only 1 latent variable and a squared correlation coefficient of 0.94. This indicates that urine from rats on the by-product diet, the extract diet, and the residue diet all contain the same dietary biomarkers and it is concluded that dimethyl sulfone and 3-hydroxyphenylacetic acid are dietary biomarkers for onion intake. Being able to detect specific dietary biomarkers is highly beneficial in the control of nutritionally enhanced functional foods. PMID:19838425

  9. Examination of an aloe vera galacturonate polysaccharide capable of in situ gelation for the controlled release of protein therapeutics

    NASA Astrophysics Data System (ADS)

    McConaughy, Shawn David

    fluorescence emission of the probe molecule 1,8-anilino-1-naphthalene sulphonic acid (1,8-ANS) as a function of polymer concentration. Correlations are drawn between viscosity experiments and measurement of zeta potential. Increased degrees of intermolecular interactions are responsible for a shift of Ce to lower polymer concentrations with increasing ionic strength. Additionally, dynamic rheology data are presented highlighting the ability of AvP to form gels at low polymer and calcium ion concentrations, exemplifying the technological potential of this polysaccharide for in-situ drug delivery. In the second section, properties of Aloe vera galacturonate hydrogels formed via Ca2+ crosslinking have been studied in regard to key parameters influencing gel formation including molecular weight, ionic strength and molar ratio of Ca2+ to COO- functionality. Dynamic oscillatory rheology and pulsed field gradient NMR (PFG-NMR) studies have been conducted on hydrogels formed at specified Ca2+ concentrations in the presence and absence of Na+ and K+ ions, in order to assess the feasibility of in situ gelation for controlled delivery of therapeutics. Aqueous Ca2+ concentrations similar to those present in nasal and subcutaneous fluids induce the formation of elastic Aloe vera polysaccharide (AvP) hydrogel networks. By altering the ratio of Ca2+ to COO- functionality, networks may be tailored to provide elastic modulus (G') values between 20 and 20,000 Pa. The Aloe vera polysaccharide exhibits time dependent phase separation in the presence of monovalent electrolytes. Thus the relative rates of calcium induced gelation and phase separation become major considerations when designing a system for in situ delivery applications where both monovalent (Na+, K+) and divalent (Ca2+) ions are present. PFG-NMR and fluorescence microscopy confirm that distinctly different morphologies are present in gels formed in the presence and absence 0.15 M NaCl. Curve fitting of theoretical models to

  10. Toxicity of an anionic detergent, dodecylbenzene sodium sulfonate, to a freshwater fish, Rita rita: determination of LC50 values by different methods.

    PubMed

    Roy, D

    1988-04-01

    LC50 values and their 95% confidence limits for various intervals of exposure to an anionic detergent, dodecylbenzene sodium sulfonate, have been determined using recommended methods. The advantages and disadvantages of these methods are discussed in light of the variations in the values. Different visible behaviors of the fish under the influence of the detergent have also been explained. PMID:3378536

  11. An Assessment of the Exposure of Americans to Perflourooctane Sulfonate: A Comparison of Estimated Intake with Values Inferred from NHANES Data

    EPA Science Inventory

    To better understand human exposure to perfluorinated compounds (PFCs), a model that assesses exposure to perfluorooctane sulfonate (PFOS) and its precursors from both an intake and a body burden perspective and combines the two with a simple pharmacokinetic (PK) model is demonst...

  12. CO2 Gas Transport Property of Sulfonated Poly(Arylenen Ether Sulfone) Copolymer Membrane.

    PubMed

    Lee, Hye Jin; Kim, Deuk Ju; Nam, Sang Yong

    2015-03-01

    The effect of functional groups such as sulfuric acid group and metal ions on the CO2 gas transport property of membranes was investigated. Sulfonated poly(arylene ether sulfone) (SPAES) was prepared by direct copolymerization with a non-sulfonated monomer and sulfonated monomer. The sulfonation degree of SPAES was controlled from 0 to 50%. Metal ions such as lithium and sodium were substituted for the protons of the -SO3H group. The thermal properties, microstructure of polymer chains, and the permeability and selectivity of membranes were evaluated. The solubility coefficient of CO2 gas increased with an increase in sulfonation degree. But the diffusivity was largely decreased and the CO2/N2 selectivity of the membrane substituted for metal ions was increased. PMID:26413703

  13. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. Link to an amendment published at 79 FR 34636, June... substance identified generically as alkylbenzene sulfonate, amine salt (PMN P-90-456) is subject...

  14. Colon Necrosis Due to Sodium Polystyrene Sulfonate with and without Sorbitol: An Experimental Study in Rats

    PubMed Central

    Ayoub, Isabelle; Oh, Man S.; Gupta, Raavi; McFarlane, Michael; Babinska, Anna; Salifu, Moro O.

    2015-01-01

    Introduction Based on a single rat study by Lillemoe et al, the consensus has been formed to implicate sorbitol rather than sodium polystyrene sulfonate (SPS) as the culprit for colon necrosis in humans treated with SPS and sorbitol. We tested the hypothesis that colon necrosis by sorbitol in the experiment was due to the high osmolality and volume of sorbitol rather than its chemical nature. Methods 26 rats underwent 5/6 nephrectomy. They were divided into 6 groups and given enema solutions under anesthesia (normal saline, 33% sorbitol, 33% mannitol, SPS in 33% sorbitol, SPS in normal saline, and SPS in distilled water). They were sacrificed after 48 hours of enema administration or earlier if they were very sick. The gross appearance of the colon was visually inspected, and then sliced colon tissues were examined under light microscopy. Results 1 rat from the sorbitol and 1 from the mannitol group had foci of ischemic colonic changes. The rats receiving SPS enema, in sorbitol, normal saline, distilled water, had crystal deposition with colonic necrosis and mucosal erosion. All the rats not given SPS survived until sacrificed at 48 h whereas 11 of 13 rats that received SPS in sorbitol, normal saline or distilled water died or were clearly dying and sacrificed sooner. There was no difference between sorbitol and mannitol when given without SPS. Conclusions In a surgical uremic rat model, SPS enema given alone or with sorbitol or mannitol seemed to cause colon necrosis and high mortality rate, whereas 33% sorbitol without SPS did not. PMID:26413782

  15. Denaturant effects on HbGp hemoglobin as monitored by 8-anilino-1-naphtalene-sulfonic acid (ANS) probe.

    PubMed

    Barros, Ana E B; Carvalho, Francisco A O; Alves, Fernanda R; Carvalho, José W P; Tabak, Marcel

    2015-03-01

    Glossoscolex paulistus extracellular hemoglobin (HbGp) stability has been monitored in the presence of denaturant agents. 8-Anilino-1-naphtalene-sulfonic acid (ANS) was used, and spectroscopic and hydrodynamic studies were developed. Dodecyltrimethylammonium bromide (DTAB) induces an increase in ANS fluorescence emission intensity, with maximum emission wavelength blue-shifted from 517 to 493 nm. Two transitions are noticed, at 2.50 and 9.50 mmol/L of DTAB, assigned to ANS interaction with pre-micellar aggregates and micelles, respectively. In oxy-HbGp, ANS binds to protein sites less exposed to solvent, as compared to DTAB micelles. In DTAB-HbGp-ANS ternary system, at pH 7.0, protein aggregation, oligomeric dissociation and unfolding were observed, while, at pH 5.0, aggregation is absent. DTAB induced unfolding process displays two transitions, one due to oligomeric dissociation and the second one, probably, to the denaturation of dissociated subunits. Moreover, guanidine hydrochloride and urea concentrations above 1.5 and 4.0 mol/L, respectively, induce the full HbGp denaturation, with reduction of ANS-bound oxy-HbGp hydrophobic patches, as noticed by fluorescence quenching up to 1.0 and 5.0 mol/L of denaturants. Our results show clearly the differences in probe sensitivity to the surfactant, in the presence and absence of protein, and new insights into the denaturant effects on HbGp unfolding. PMID:25546245

  16. Synthesis and characterization of sulfonated poly(ether sulfone)s containing mesonaphthobifluorene for polymer electrolyte membrane fuel cell.

    PubMed

    Lim, Youngdon; Seo, Dongwan; Lee, Soonho; Hossain, Md Awlad; Lim, Jinseong; Lee, Sangyoung; Hong, Taehoon; Kim, Whangi

    2014-10-01

    The novel sulfonated poly(ether sulfone)s containing mesonaphthobifluorene (MNF) moiety were synthesized and characterized their properties. The prepared polymers have highly conjugated aromatic structure due to the MNF group which is an allotrope of carbon and one atom thick planar sheets of sp2-bonded carbon atoms. Poly(ether sulfone)s bearing tetraphenylethylene on polymer backbone were synthesized by polycondensation and followed intra-cyclization from tetraphenylethylene to form MNF by Friedel-craft reaction with Lewis acid (FeCl3). The sulfonation was performed selectively on MNF units with conc. sulfuric acid. The structural properties of the sulfonated polymers were investigated by 1H-NMR spectroscopy. The membranes were studied by ion exchange capacity (IEC), water uptake, and proton conductivity. The synthesized polymer electrolyte membranes showed better thermal and dimensional stabilities owing to the inducted highly conjugated aromatic structure in the polymer backbone. The water uptake of the synthesized membranes ranged from 23-52%, compared with 32.13% for Nafion 211 at 80 degrees C. The synthesized membranes exhibited proton conductivities (80 degrees C, RH 90%) of 74.6-100.4 mS/cm, compared with 102.7 mS/cm for Nafion 211. PMID:25942900

  17. Morphology of a blend of zinc neutralized sulfonated poly(phenylene oxide) or polystyrene and an amino silicone

    SciTech Connect

    Jones, A.A.; Inglefield, P.T.; Zhang, Changlai; Bergquist, P

    1996-12-31

    A polymer blend of an ionomer based on zinc neutralized sulfonated poly(phenylene oxide) or polystyrene with a silicone copolymer containing 6.45% propylamine groups in place of one of the methyl groups on a backbone silicon was prepared. Carbon-13 magic angle spinning spectra show coordination of the amine, by the zinc ions. Morphological characterization was made by NMR spectroscopy based on proton spin diffusion, by small angle x-ray scattering and by energy filtered transmission electron microscopy. All experiments show domains in the range of 1 to 1000 nm and domain size can be controlled by the extent of coordination of the amine groups by the zinc ions and by thermal history. The different lead to an apparent hierarchy of domain sizes. The NMR domains, 2 to 10 nm, where contrast is produced by differences in chain mobility. Small angle x-ray scattering indicates domains of 16 nm while electron in the range of 100 to 1000 nm. The variation of the domain size between experiments may reflect the different sources of contrast in each cam.

  18. Synthesis of a Sulfonated Two-Dimensional Covalent Organic Framework as an Efficient Solid Acid Catalyst for Biobased Chemical Conversion.

    PubMed

    Peng, Yongwu; Hu, Zhigang; Gao, Yongjun; Yuan, Daqiang; Kang, Zixi; Qian, Yuhong; Yan, Ning; Zhao, Dan

    2015-10-12

    Because of limited framework stability tolerance, de novo synthesis of sulfonated covalent organic frameworks (COFs) remains challenging and unexplored. Herein, a sulfonated two-dimensional crystalline COF, termed TFP-DABA, was synthesized directly from 1,3,5-triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid through a previously reported Schiff base condensation reaction, followed by irreversible enol-to-keto tautomerization, which strengthened its structural stability. TFP-DABA is a highly efficient solid acid catalyst for fructose conversion with remarkable yields (97 % for 5-hydroxymethylfurfural and 65 % for 2,5-diformylfuran), good chemoselectivity, and good recyclability. The present study sheds light on the de novo synthesis of sulfonated COFs as novel solid acid catalysts for biobased chemical conversion. PMID:26448524

  19. An energy-efficient process for decomposing perfluorooctanoic and perfluorooctane sulfonic acids using dc plasmas generated within gas bubbles

    NASA Astrophysics Data System (ADS)

    Yasuoka, K.; Sasaki, K.; Hayashi, R.

    2011-06-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are environmentally harmful and persistent substances. Their decomposition was investigated using dc plasmas generated within small gas bubbles in a solution. The plasma characteristics including discharge voltage, voltage drop in the liquid, plasma shape and the emission spectrum were examined with different gases. The decomposition rate and energy efficiency were evaluated by measuring the concentration of fluoride and sulfate ions released from PFOA/PFOS molecules. The concentration of fluoride ions and energy efficiency in the treatment of a PFOS solution were 17.7 mg l-1 (54.8% of the initial amount of fluorine atoms) and 26 mg kWh-1, respectively, after 240 min of operation. The addition of scavengers of hydroxyl radicals and hydrated electrons showed little effect on the decomposition. The decomposition processes were analyzed with an assumption that positive species reacted with PFOA/PFOS molecules at the boundary of the plasma-solution surface. This type of plasma showed a much higher decomposition energy efficiency compared with energy efficiencies reported in other studies.

  20. Self-organization of surfactant molecules on solid surface: an STM study of sodium alkyl sulfonates [rapid communication

    NASA Astrophysics Data System (ADS)

    Yin, Xiu-Li; Wan, Li-Jun; Yang, Zheng-Yu; Yu, Jia-Yong

    2005-02-01

    Adsorption and self-organization of sodium alkyl sulfonates (STS and SHS) on HOPG have been studied by using in situ scanning tunneling microscopy (STM). Both SHS and STS molecules adsorb on HOPG surface and form long-range well-ordered monolayers. The molecular rows and the axes of alkyl chain of the molecules cross each other at angles of 60° and 90° in the STS and SHS layers, respectively. Molecular details such as sulfonate functional group (head) and alkyl chain are clearly imaged. The neighboring molecules in different rows form a "head to head" configuration. Structural models for the molecular arrangement of the two adlayers are proposed.

  1. A Durable Alternative for Proton-Exchange Membranes: Sulfonated Poly(Benzoxazole Thioether Sulfone)s

    SciTech Connect

    Zhao, Dan; Li, Jin Hui; Song, Min Kyu; Yi, Baolian; Zhang, Huamin; Liu, Meilin

    2011-02-24

    To develop a durable proton-exchange membrane (PEM) for fuel-cell applications, a series of sulfonated poly(benzoxazole thioether sulfone)s ( SPTESBOs) are designed and synthesized, with anticipated good dimensional stability (via acid–base cross linking), improved oxidative stability against free radicals (via incorporation of thioether groups), and enhanced inherent stability (via elimination of unstable end groups) of the backbone. The structures and the degree of sulfonation of the copolymers are characterized using Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy ({sup 1}H NMR and {sup 19}F NMR). The electrochemical stabilities of the monomers are examined using cyclic voltammetry in a typical three-electrode cell configuration. The physicochemical properties of the membranes vital to fuel-cell performance are also carefully evaluated under conditions relevant to fuel-cell operation, including chemical and thermal stability, proton conductivity, solubility in different solvents, water uptake, and swelling ratio. The new membranes exhibit low dimensional change at 25°C to 90°C and excellent thermal stability up to 250°C. Upon elimination of unstable end groups, the co-polymers display enhanced chemical resistance and oxidative stability in Fenton's test. Further, the SPTESBO-HFB-60 (HFB-60=hexafluorobenzene, 60 mol% sulfone) membrane displays comparable fuel-cell performance to that of an NRE 212 membrane at 80°C under fully humidified condition, suggesting that the new membranes have the potential to be more durable but less expensive for fuel-cell applications.

  2. Sulfonated polyphenylene polymers

    DOEpatents

    Cornelius, Christopher J.; Fujimoto, Cy H.; Hickner, Michael A.

    2007-11-27

    Improved sulfonated polyphenylene compositions, improved polymer electrolyte membranes and nanocomposites formed there from for use in fuel cells are described herein. The improved compositions, membranes and nanocomposites formed there from overcome limitations of Nafion.RTM. membranes.

  3. Crystal structure of zwitterionic bisimidazolium sulfonates

    NASA Astrophysics Data System (ADS)

    Kohmoto, Shigeo; Okuyama, Shinpei; Yokota, Nobuyuki; Takahashi, Masahiro; Kishikawa, Keiki; Masu, Hyuma; Azumaya, Isao

    2012-05-01

    Crystal structures of three zwitterionic bisimidazolium salts 1-3 in which imidazolium sulfonate moieties were connected with aromatic linkers, p-xylylene, 4,4'-dimethylenebiphenyl, and phenylene, respectively, were examined. The latter two were obtained as hydrates. An S-shaped molecular structure in which the sulfonate moiety was placed on the imidazolium ring was observed for 1. A helical array of hydrated water molecules was obtained for 2 while a linear array of hydrated water molecules was observed for 3.

  4. Addition of sulfonated silicon dioxide on an anode catalyst layer to improve the performance of a self-humidifying proton exchange membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Lin, Chien-Liang; Hsu, Shih-Chieh; Ho, Wei-Yu

    2016-03-01

    Sulfonated SiO2 was added on an anode catalyst layer to manufacture a hygroscopic electrode for self-humidifying proton exchange membrane fuel cells (PEMFCs). The inherent humidity of a proton exchange membrane (PEM) determines the electrical performance of PEMFCs. To maintain the high moisture content of the PEM, self-humidifying PEMFCs can use the water produced by the fuel cell reaction and, thus, do not require external humidification. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and water contact angle measurement tests were performed to characterize the structures and properties of sulfonated SiO2 and the related electrodes, and the electric current and voltage (I-V) performance curve tests for the fuel cells were conducted under differing gas humidification conditions. When 0.01mg/cm2 of sulfonated SiO2 was added, the electrical performance of the fuel cells (50∘C) increased 29% and 59% when the fuel cell reaction gases were humidified at 70∘C and 50∘C, respectively.

  5. Phytoremediation of sulfonated Remazol Red dye and textile effluents by Alternanthera philoxeroides: An anatomical, enzymatic and pilot scale study.

    PubMed

    Rane, Niraj R; Chandanshive, Vishal V; Watharkar, Anuprita D; Khandare, Rahul V; Patil, Tejas S; Pawar, Pankaj K; Govindwar, Sanjay P

    2015-10-15

    Alternanthera philoxeroides Griseb. a macrophyte was found to degrade a highly sulfonated textile dye Remazol Red (RR) completely within 72 h at a concentration of 70 mg L(-1). An induction in the activities of azoreductase and riboflavin reductase was observed in root and stem tissues; while the activities of lignin peroxidase, laccase and DCIP reductase were induced in leaf tissues. Some enzymes namely tyrosinase, veratryl alcohol oxidase, catalase and superoxide dismutase displayed an increase in their activity in all the tissues in response of 72 h exposure to Remazol Red. There was a marginal reduction in contents of chlorophyll a (20%), chlorophyll b (5%) and carotenoids (16%) in the leaves when compared to control plants. A detailed anatomical study of the stem during uptake and treatment revealed a stepwise mechanism of dye degradation. UV-vis spectrophotometric and high performance thin layer chromatographic analyses confirmed the removal of parent dye from solution. Based on the enzymes activities and gas chromatography-mass spectroscopic analysis of degradation products, a possible pathway of phytotransformation of RR was proposed which revealed the formation of 4-(phenylamino)-1,3,5-triazin-2-ol, naphthalene-1-ol and 3-(ethylsulfonyl)phenol. Toxicity study on Devario aequipinnatus fishes showed that the anatomy of gills of fishes exposed to A. philoxeroides treated RR was largely protected. The plants were further explored for rhizofiltration experiments in a pilot scale reactor. A. philoxeroides could decolorize textile industry effluent of varying pH within 96 h of treatment which was evident from the significant reductions in the values of American dye manufacturers' institute color, chemical oxygen demand, biological oxygen demand, total dissolved and total suspended solids. PMID:26164661

  6. An experimental and theoretical method for determination of standard electrode potential for the redox couple diphenyl sulfone/diphenyl sulfide

    NASA Astrophysics Data System (ADS)

    Song, Y. Z.; Wei, K. X.; Lv, J. S.

    2013-12-01

    DFT calculations were performed for diphenyl sulfide and diphenyl sulfone. The electrochemistry of diphenyl sulfide on the gold electrode was investigated by cyclic voltammety and the results show that standard electrode potential for redox couple diphenyl sulfone/diphenyl sulfide is 1.058 V, which is consistent with that of 1.057 calculated at B3LYP/6-31++G( d, p)-IEFPCM level. The front orbit theory and Mulliken charges of molecular explain well on the oxidation of diphenyl sulfide in oxidative desulfurization. According to equilibrium theory the experimental equilibrium constant in the oxidative desulfurization of H2O2, is 1.17 × 1048, which is consistent with the theoretical equilibrium constant is 2.18 × 1048 at B3LYP/6-31++G( d, p)-IEFPCM level.

  7. Phase equilibria in a system of aqueous arginine with an octane solution of sulfonic acid

    NASA Astrophysics Data System (ADS)

    Kuvaeva, Z. I.; Koval'chuk, I. V.; Vodop'yanova, L. A.; Soldatov, V. S.

    2013-05-01

    The extraction of arginine (Arg) from aqueous salt (0.1 M NaCl) solutions with a sulfo extractant in a wide range of pH values and amino acid concentrations was studied. The 0.1 M solution of dinonylnaphthalenesulfonic acid (HD) in octane was used as an extractant. The degree of extraction was found to be high at pH 0.8-9.0. This can be explained by the effect of additional intermolecular interactions in the extractant phase involving the guanidine group of Arg.

  8. Sulfonated Polyamide Based IPMCs

    NASA Astrophysics Data System (ADS)

    Park, Il-Seok; Bae, Chulsung; Jo, Tae Soo; Truong, Justina; Kim, Sang-Mun; Kim, Kwang J.; Yim, Woosoon; Lee, Joon-Soo

    2009-03-01

    In this study, we introduce a newly developed Ionic Polymer-Metal Composite (IPMC) family that is manufactured using a novel ionic exchange membrane-a randomly sulfonated fluoropoly(ether amide) (TFIPA-90)-as the base material. The thermal behavior and mechanical properties of the ionic polymer were probed by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Electrochemical properties and the actuation performance of the TFIPA-90 based IPMCs were also investigated in this study. The stiffness of the TFIPA polymer was significantly higher than that of Nafion® and much noted at high temperatures (>100 oC). The thermal behavior of the TFIPA polymer also showed better stability than Nafion(R) at high temperatures due to the more rigid chemical structure of the ionomer. As an actuator, a new IPMC prepared from TFIPA-90 showed improved performance with rapid response time to the electric field and a large bending displacement. The TFIPA-based IPMC may be useful for microwave-driven robotic applications.

  9. MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE IN THE RAT

    EPA Science Inventory

    MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE IN THE RAT.
    C. Lau and J.M. Rogers, Reproductive Toxicology Division, NHEERL, ORD, USEPA, Research Triangle Park, NC, USA

    Perfluorooctane sulfonate (PFOS), an environmentally persistent compound used ...

  10. Radiation grafted and sulfonated (FEP-g-polysterene) - An alternative to perfluorinated membranes for PEM fuel cells?

    NASA Astrophysics Data System (ADS)

    Buechi, F. N.; Gupta, B.; Rouilly, M.; Hauser, P. C.; Chapiro, A.; Scherer, G. G.

    Partially fluorinated proton exchange membranes (PEMs) were synthesized for fuel cell applications by simultaneous radiation grafting of styrene on FEP films followed by sulfonation. Properties of the synthesized membranes can be tailored by varying the degree of grafting and crosslinking. The performance of these membranes was tested in H2/O2 fuel cells. Long time testing showed steady performance for high grafted membranes over periods of more than 300 h at a cell temperature of 60 C. Low grafted membranes and the Morgane CDS membrane showed considerable decay of cell power on the same time scale. A fast degradation of all membranes occurred at a cell temperature of 80 C. It is noted that grafting in film form makes this process a potentially cheap and easy technique for the preparation of solid polymer fuel cell electrolytes.

  11. Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC.

    PubMed

    Jang, Hohyoun; Islam, Md Monirul; Lim, Youngdon; Hossain, Md Awlad; Cho, Younggil; Joo, Hyunho; Kim, Whangi; Jeon, Heung-Seok

    2014-10-01

    Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4'-(2,2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4, 4'-sulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211. PMID:25942869

  12. Aminooxylation Horner-Wadsworth-Emmons Sequence for the Synthesis of Enantioenriched γ-Functionalized Vinyl Sulfones.

    PubMed

    Doherty, William; Evans, Paul

    2016-02-19

    An operationally simple protocol for the synthesis of γ-hydroxy vinyl sulfones has been developed using a proline-based aldehyde aminooxylation, followed by a vinyl sulfone forming Horner-Wadsworth-Emmons olefination. The adducts, formed in high enantiopurity, were subsequently converted to γ-azido vinyl sulfones, and azide-alkyne click chemistry enabled the synthesis of vinyl sulfone-based triazoles as potential nonpeptidic cysteine protease inhibitors. PMID:26818590

  13. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  14. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aryl sulfonate of a fatty acid mixture... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  15. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  16. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  17. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  18. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  19. 40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt...

  20. Secondary recovery process utilizing sulfonated polyphenols

    SciTech Connect

    Hunter, W.D.

    1980-10-07

    Hydrocarbons are recovered from subterranean formations by injecting into a hydrocarbon bearing formation via an injection well a fluid comprising water containing a small amount of a water-soluble, sulfonated, ethoxylated polyphenol, forcing the said fluid through the formation and recovering hydrocarbons through a production well. The fluids employed may, if desired, contain an alkaline agent such as sodium hydroxide.

  1. Perfluorooctane sulfonate (PFOS) depletion in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is used as a surfactant in several manufactured consumer products but is also a breakdown product from other chemical surfactants. As a result of its extensive use, PFOS is ubiquitous in the environment and is often detected in biosoli...

  2. Correlating electronic structure and chemical durability of sulfonated poly(arylene ether sulfone)s

    NASA Astrophysics Data System (ADS)

    Lawrence, Jimmy; Yamashita, Koichi; Yamaguchi, Takeo

    2015-04-01

    Many different proton-conducting polymeric materials have been developed for polymer electrolyte membrane fuel cells (PEMFCs). The development of perfluorosulfonic acid-based, polymer electrolyte membranes (PFSA-PEMs) was followed by aromatic hydrocarbon-based PEMs (HC-PEMs), which allow for tailored design and optimization of their molecular structures. Although many new PFSA-PEMs and HC-PEMs have shown promising proton conductivity and thermal stability, chemical degradation of these materials in an oxidizing environment remains a significant technical barrier in PEMFC development. Here, we used accelerated degradation tests and electronic structure analysis to examine the chemical stability of sulfonated poly(arylene ether sulfone) (SPES) copolymers, a highly thermally stable HC-PEM. HOMO levels, the presence of main chain-protecting steric groups, and HOMO-LUMO location along the main chain have significant effects on the chain scission modes and degradation rate of SPES copolymers. Rational design of HC-PEMs to suppress midpoint scission can open many opportunities in the development of highly robust polymer electrolytes for fuel cell and other energy storage applications.

  3. Sulfonated Polymerized Ionic Liquid Block Copolymers.

    PubMed

    Meek, Kelly M; Elabd, Yossef A

    2016-07-01

    The successful synthesis of a new diblock copolymer, referred to as sulfonated polymerized ionic liquid (PIL) block copolymer, poly(SS-Li-b-AEBIm-TFSI), is reported, which contains both sulfonated blocks (sulfonated styrene: SS) and PIL blocks (1-[(2-acryloyloxy)ethyl]-3-butylimidazolium: AEBIm) with both mobile cations (lithium: Li(+) ) and mobile anions (bis(trifluoromethylsulfonyl)imide: TFSI(-) ). Synthesis consists of polymerization via reversible addition-fragmentation chain transfer, followed by post-functionalization reactions to covalently attach the imidazolium cations and sulfonic acid anions to their respective blocks, followed by ion exchange metathesis resulting in mobile Li(+) cations and mobile TFSI(-) anions. Solid-state films containing 1 m Li-TFSI salt dissolved in ionic liquid result in an ion conductivity of >1.5 mS cm(-1) at 70 °C, where small-angle X-ray scattering data indicate a weakly ordered microphase-separated morphology. These results demonstrate a new ion-conducting block copolymer containing both mobile cations and mobile anions. PMID:27125600

  4. Phase Behavior of Symmetric Sulfonated Block Copolymers

    SciTech Connect

    Park, Moon Jeong; Balsara, Nitash P.

    2008-08-21

    Phase behavior of poly(styrenesulfonate-methylbutylene) (PSS-PMB) block copolymers was studied by varying molecular weight, sulfonation level, and temperature. Molecular weights of the copolymers range from 2.9 to 117 kg/mol. Ordered lamellar, gyroid, hexagonally perforated lamellae, and hexagonally packed cylinder phases were observed in spite of the fact that the copolymers are nearly symmetric with PSS volume fractions between 0.45 and 0.50. The wide variety of morphologies seen in our copolymers is inconsistent with current theories on block copolymer phase behavior such as self-consistent field theory. Low molecular weight PSS-PMB copolymers (<6.2 kg/mol) show order-order and order-disorder phase transitions as a function of temperature. In contrast, the phase behavior of high molecular weight PSS-PMB copolymers (>7.7 kg/mol) is independent of temperature. Due to the large value of Flory-Huggins interaction parameter, x, between the sulfonated and non-sulfonated blocks, PSS-PMB copolymers with PSS and PMB molecular weights of 1.8 and 1.4 kg/mol, respectively, show the presence of an ordered gyroid phase with a 2.5 nm diameter PSS network. A variety of methods are used to estimate x between PSS and PMB chains as a function of sulfonation level. Some aspects of the observed phase behavior of PSS-PMB copolymers can be rationalized using x.

  5. Magnetic and dielectric properties of sulfonated (S) poly[(styrene)-(ethylene-co-butylene)]-styrene (SEBS) block copolymer/magnetic metal oxide nanocomposites synthesized via an in-situ precipitation method

    NASA Astrophysics Data System (ADS)

    Peddini, Sateesh Kumar

    Block copolymer/magnetic metal oxide nanocomposites were synthesized by growing metal oxide nanoparticles (cobalt ferrite, CoFe2O 4 and iron oxide, alpha-Fe2O3) in sulfonated (s) poly (styrene) (PS) block domains of sulfonated poly [(styrene)-(ethylene-co-butylene)-(styrene)] (SEBS) BCP preformed films via an in-situ precipitation method by dissolving the salts of respective metal chloride (s) in a suitable solvent that selectively swells the sPS regions. Inorganic uptake was determined using thermogravimetric analysis (TGA), and it was observed that none of the samples incorporated more than 5 wt % of the inorganic component. Dynamical mechanical analysis was used to observe the changes in the glass transition temperatures (T g) in both blocks of the BCP by plotting tan delta vs. temperature responses in tensile mode on all samples. The results showed that the T g of the sPS block domains increased with sulfonation level and further increased with the incorporation of both nanoparticles in the same blocks, indicating that growth of nanoparticles takes place only in sPS blocks. The crystalline structure of the nanoparticles was observed using wide angle X-ray diffractometry (WAXD), and it was determined that cobalt iron oxide nanoparticles in 20 mole % sulfonated SEBS exhibited an inverse spinel structure confirming the structure to be CoFe2O4. And with iron oxide nanoparticles in 10 mole % sulfonated SEBS exhibiting a hematite (alpha-Fe2O 3) phase. Transmission electron microscopy (TEM) was used to investigate the particle size and distribution of nanoparticles in sBCP matrices at all sulfonation levels. Select area electron diffraction in TEM was used to determine crystalline structures of individual nanoparticles to compare with the structure observed from WAXD. The changes in thickness of interfaces between the individual PS and EB block domains with increase in sulfonation of PS blocks were investigated semi-quantitatively using tapping mode atomic force

  6. An investigation of long and short range ion motions within the cluster morphology of electrolyte-containing perfluoro-sulfonate ionomer membranes

    SciTech Connect

    Su, S.

    1992-01-01

    An equivalent circuit model was postulated for PFSI (perfluoro-sulfanate-ionomer) polymers. It successfully models three different dielectric relaxation mechanisms taking place within long and short sidechain PFSI's in an alternating electric field. The three dielectric processes are long-range ion inter-cluster hopping in the low frequency region, short-range intra-cluster polarization occurred in frequencies at about 10[sup 3] to 10[sup 6] Hz, and Debye-like orientation of water molecules taking place at very high frequencies. When membranes are annealed in the proximity of the glass transition temperature of ionic clusters, the packing of sulfonate groups becomes more efficient. This is by the fact that the symmetrical parameter of the distribution of relaxation time of the Cole-Cole equation increases with annealing time. The cluster activities of the long and short sidechain polymers act differently in different electrolyte solutions. The sidechains of the long sidechain polymer act like a spring, it contracts while the material was equilibrated in low concentration solutions and it expands as equilibrated in concentrated solutions. The cluster dimension of the long sidechain material does not vary too much. The cluster dimension of short sidechain polymers can vary significantly on different electrolyte solutions.

  7. Evidence for an unrecognized secondary anthropogenic source of organosulfates and sulfonates: gas-phase oxidation of polycyclic aromatic hydrocarbons in the presence of sulfate aerosol.

    PubMed

    Riva, Matthieu; Tomaz, Sophie; Cui, Tianqu; Lin, Ying-Hsuan; Perraudin, Emilie; Gold, Avram; Stone, Elizabeth A; Villenave, Eric; Surratt, Jason D

    2015-06-01

    In the present study, formation of aromatic organosulfates (OSs) from the photo-oxidation of polycyclic aromatic hydrocarbons (PAHs) was investigated. Naphthalene (NAP) and 2-methylnaphthalene (2-MeNAP), two of the most abundant gas-phase PAHs and thought to represent "missing" sources of urban SOA, were photochemically oxidized in an outdoor smog chamber facility in the presence of nonacidified and acidified sulfate seed aerosol. Effects of seed aerosol composition, acidity and relative humidity on OS formation were examined. Chemical characterization of SOA extracts by ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry revealed the formation of OSs and sulfonates from photo-oxidation in the presence of sulfate seed aerosol. Many of the organosulfur compounds identified in the smog chamber extracts were also measured in urban fine aerosol collected at Lahore, Pakistan, and Pasadena, USA, demonstrating that PAH photo-oxidation in the presence of sulfate aerosol is a hitherto unrecognized source of anthropogenic secondary organosulfur compounds, and providing new PAH SOA tracers. PMID:25879928

  8. Novel sulfonated poly (ether ether ketone)/phosphonic acid-functionalized titania nanohybrid membrane by an in situ method for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Wu, Hong; Cao, Ying; Li, Zhen; He, Guangwei; Jiang, Zhongyi

    2015-01-01

    Sulfonated poly (ether ether ketone)/phosphonic acid-functionalized titania nanohybrid membranes are prepared by an in situ method using titanium tetrachloride (TiCl4) as inorganic precursor and amino trimethylene phosphonic acid (ATMP) as modifier. Phosphonic acid-functionalized titania nanoparticles with a uniform particle size of ∼50 nm are formed and dispersed homogeneously in the SPEEK matrix with good interfacial compatibility. Accordingly, the nanohybrid membranes display remarkably enhanced proton conduction property due to the incorporation of additional sites for proton transport and the formation of well-connected channels by bridging the hydrophilic domains in SPEEK matrix. The nanohybrid membrane with 6 wt. % of phosphonic acid-functionalized titania nanoparticles exhibits the highest proton conductivity of 0.334 S cm-1 at 65 °C and 100% RH, which is 63.7% higher than that of pristine SPEEK membrane. Furthermore, the as-prepared nanohybrid membranes also show elevated thermal and mechanical stabilities as well as decreased methanol permeability.

  9. An optimized method for the determination of perfluorooctanoic acid, perfluorooctane sulfonate and other perfluorochemicals in different matrices using liquid chromatography/ion-trap mass spectrometry.

    PubMed

    Dolman, Sebastiaan; Pelzing, Matthias

    2011-07-15

    Perfluorochemicals (PFC's) are widely spread in the environment and have been detected in blood of wildlife and humans world-wide. Recently, various toxic effects of PFC's in laboratory rats have been demonstrated, resulting in increased government concerns regarding the presence of PFC's in the environment and the implications they have on human health. In the last decade, various analytical methods have been developed for the analysis of PFC's in different matrices whereby the majority of methods have utilised liquid chromatography coupled with mass spectrometry (LC-MS). Here we describe an optimized method for the quantitation of PFC's, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), in food packaging, polytetrafluoroethylene (PTFE) sealant tape and drinking water. The method involved PFC's extraction via off-line SPE followed by separation using reversed-phase liquid chromatography on a Phenyl-Hexyl column coupled with ion-trap (IT) mass spectrometric detection. The optimized approach minimized ion-suppression effects commonly seen with conventional elution buffers, improving detection limits down to 25 pg/mL and allowed effective quantitation down to 50 pg/mL for PFOA and PFOS. The optimized LC-MS method detected PFOA and other PFC's in microwave popcorn packaging and PFOA in PTFE sealant tape in the low μg/kg. In all samples, PFOS was not detected. PMID:21700512

  10. Sorption of sodium dodecylbenzene sulfonate by montmorillonite.

    PubMed

    Yang, Kun; Zhu, Lizhong; Xing, Baoshan

    2007-01-01

    Sorption of linear alkylbenzene sulfonates by soils and sediments is an important process that may affect their fate, transport, toxicity and their application in remediation of contaminated soil and groundwater. In this study, batch experiments were conducted to elucidate the sorption of a widely used anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), by montmorillonite. It was observed that: (i) SDBS was sorbed significantly by montmorillonite saturated with Ca(2+), but little by Na-saturated montmorillonite; (ii) the amount of SDBS sorbed by Ca(2+)-montmorillonite was enhanced by NaCl; and (iii) no significant intercalation of SDBS into Ca(2+)-montmorillonite was observed by X-ray diffraction (XRD) analysis. These results indicate that the removal of SDBS by Ca(2+)-montmorillonite was primarily attributed to the precipitation between DBS(-) and Ca(2+) in solution which was released from montmorillonite via cation exchange. These results will help us to understand the sorption behavior and environmental effects of anionic surfactants. PMID:16759775

  11. High Lipophilicty of Perfluoroalkyl Carboxylate and Sulfonate

    PubMed Central

    Jing, Ping; Rodgers, Patrick J.; Amemiya, Shigeru

    2009-01-01

    Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, ∼2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

  12. Thermal stability of sulfonated polymers

    SciTech Connect

    Audibert, A.; Argillier, J.F.

    1995-11-01

    Polyacrylamides which are used in oil applications i.e. polymer flooding and water based muds, are hydrolyzed versus time and temperature. This leads to a lack of tolerance towards electrolyte contamination and to a rapid degradation inducing a loss of their properties. Modifications of polyacrylamide structure have been proposed to postpone their thermal stability to higher temperatures. Monomers such as acrylamido methylpropane sulfonate (AMPS) or sulfonated styrene/maleic anhydride can be used to prevent acrylamide comonomer from hydrolysis. The aim of this work is to study under controlled conditions, i.e. anaerobic atmosphere, neutral pH, the stability of sulfonated polymers in order to distinguish between hydrolysis and radical degradation reactions. It has been observed that up to 100 C, the AMPS group is stable and protects the acrylamide function from hydrolysis up to 80%. At higher temperature, even the hydrolysis of the AMPS group occurs, giving acrylate and {beta},{beta} dimethyl taurine, with a kinetics that depends on temperature and time. Degradation in terms of molecular weight then occurs indicating that it follows a radical decarboxylation reaction. It can be limited either by the use of free radical scavenger or when the polymer is in the presence of a mineral phase such as bentonite. These results provide valuable data for the determination of the limits of use of sulfonated copolymers and guidelines for optimizing chemical structure of sulfonated polymers used in water based formulation, in particular to enhance their thermal stability.

  13. An Introduction to Multivariate Curve Resolution-Alternating Least Squares: Spectrophotometric Study of the Acid-Base Equilibria of 8-Hydroxyquinoline-5-Sulfonic Acid

    ERIC Educational Resources Information Center

    Rodriguez-Rodriguez, Cristina; Amigo, Jose Manuel; Coello, Jordi; Maspoch, Santiago

    2007-01-01

    A spectrophotometric study of the acid-base equilibria of 8-hydroxyquinoline-5-sulfonic acid to describe the multivariate curve resolution-alternating least squares algorithm (MCR-ALS) is described. The algorithm provides a lot of information and hence is of great importance for the chemometrics research.

  14. 1-Anilino-8-Naphthalene Sulfonate (ANS) Is Not a Desirable Probe for Determining the Molten Globule State of Chymopapain

    PubMed Central

    Qadeer, Atiyatul; Rabbani, Gulam; Zaidi, Nida; Ahmad, Ejaz; Khan, Javed M.; Khan, Rizwan H.

    2012-01-01

    The molten globule (MG) state of proteins is widely detected through binding with 1-anilino-8-naphthalene sulphonate (ANS), a fluorescent dye. This strategy is based upon the assumption that when in molten globule state, the exposed hydrophobic clusters of protein are readily bound by the nonpolar anilino-naphthalene moiety of ANS molecules which then produce brilliant fluorescence. In this work, we explored the acid-induced unfolding pathway of chymopapain, a cysteine proteases from Carica papaya, by monitoring the conformational changes over a pH range 1.0–7.4 by circular dichroism, intrinsic fluorescence, ANS binding, acrylamide quenching, isothermal titration calorimetry (ITC) and dynamic light scattering (DLS). The spectroscopic measurements showed that although maximum ANS fluorescence intensity was observed at pH 1.0, however protein exhibited ∼80% loss of secondary structure which does not comply with the characteristics of a typical MG-state. In contrast at pH 1.5, chymopapain retains substantial amount of secondary structure, disrupted side chain interactions, increased hydrodynamic radii and nearly 30-fold increase in ANS fluorescence with respect to the native state, indicating that MG-state exists at pH 1.5 and not at pH 1.0. ITC measurements revealed that ANS molecules bound to chymopapain via hydrophobic interaction were more at pH 1.5 than at pH 1.0. However, a large number of ANS molecules were also involved in electrostatic interaction with protein at pH 1.0 which, together with hydrophobically interacted molecules, may be responsible for maximum ANS fluorescence. We conclude that maximum ANS-fluorescence alone may not be the criteria for determining the MG of chymopapain. Hence a comprehensive structural analysis of the intermediate is essentially required. PMID:23209794

  15. 1-Anilino-8-naphthalene sulfonate (ANS) is not a desirable probe for determining the molten globule state of chymopapain.

    PubMed

    Qadeer, Atiyatul; Rabbani, Gulam; Zaidi, Nida; Ahmad, Ejaz; Khan, Javed M; Khan, Rizwan H

    2012-01-01

    The molten globule (MG) state of proteins is widely detected through binding with 1-anilino-8-naphthalene sulphonate (ANS), a fluorescent dye. This strategy is based upon the assumption that when in molten globule state, the exposed hydrophobic clusters of protein are readily bound by the nonpolar anilino-naphthalene moiety of ANS molecules which then produce brilliant fluorescence. In this work, we explored the acid-induced unfolding pathway of chymopapain, a cysteine proteases from Carica papaya, by monitoring the conformational changes over a pH range 1.0-7.4 by circular dichroism, intrinsic fluorescence, ANS binding, acrylamide quenching, isothermal titration calorimetry (ITC) and dynamic light scattering (DLS). The spectroscopic measurements showed that although maximum ANS fluorescence intensity was observed at pH 1.0, however protein exhibited ∼80% loss of secondary structure which does not comply with the characteristics of a typical MG-state. In contrast at pH 1.5, chymopapain retains substantial amount of secondary structure, disrupted side chain interactions, increased hydrodynamic radii and nearly 30-fold increase in ANS fluorescence with respect to the native state, indicating that MG-state exists at pH 1.5 and not at pH 1.0. ITC measurements revealed that ANS molecules bound to chymopapain via hydrophobic interaction were more at pH 1.5 than at pH 1.0. However, a large number of ANS molecules were also involved in electrostatic interaction with protein at pH 1.0 which, together with hydrophobically interacted molecules, may be responsible for maximum ANS fluorescence. We conclude that maximum ANS-fluorescence alone may not be the criteria for determining the MG of chymopapain. Hence a comprehensive structural analysis of the intermediate is essentially required. PMID:23209794

  16. Examination of an aloe vera galacturonate polysaccharide capable of in situ gelation for the controlled release of protein therapeutics

    NASA Astrophysics Data System (ADS)

    McConaughy, Shawn David

    fluorescence emission of the probe molecule 1,8-anilino-1-naphthalene sulphonic acid (1,8-ANS) as a function of polymer concentration. Correlations are drawn between viscosity experiments and measurement of zeta potential. Increased degrees of intermolecular interactions are responsible for a shift of Ce to lower polymer concentrations with increasing ionic strength. Additionally, dynamic rheology data are presented highlighting the ability of AvP to form gels at low polymer and calcium ion concentrations, exemplifying the technological potential of this polysaccharide for in-situ drug delivery. In the second section, properties of Aloe vera galacturonate hydrogels formed via Ca2+ crosslinking have been studied in regard to key parameters influencing gel formation including molecular weight, ionic strength and molar ratio of Ca2+ to COO- functionality. Dynamic oscillatory rheology and pulsed field gradient NMR (PFG-NMR) studies have been conducted on hydrogels formed at specified Ca2+ concentrations in the presence and absence of Na+ and K+ ions, in order to assess the feasibility of in situ gelation for controlled delivery of therapeutics. Aqueous Ca2+ concentrations similar to those present in nasal and subcutaneous fluids induce the formation of elastic Aloe vera polysaccharide (AvP) hydrogel networks. By altering the ratio of Ca2+ to COO- functionality, networks may be tailored to provide elastic modulus (G') values between 20 and 20,000 Pa. The Aloe vera polysaccharide exhibits time dependent phase separation in the presence of monovalent electrolytes. Thus the relative rates of calcium induced gelation and phase separation become major considerations when designing a system for in situ delivery applications where both monovalent (Na+, K+) and divalent (Ca2+) ions are present. PFG-NMR and fluorescence microscopy confirm that distinctly different morphologies are present in gels formed in the presence and absence 0.15 M NaCl. Curve fitting of theoretical models to

  17. Phycotoxicity of linear alkylbenzene sulfonate

    SciTech Connect

    Chawla, G.; Viswanathan, P.N.; Devi, S.

    1988-04-01

    Dose- and time-dependent effects of linear alkylbenzene sulfonate, a major component of synthetic detergent, to the blue-green alga Nostoc muscorum, were studied under laboratory conditions. Toxicity was evident, at doses above 0.001%, from the decrease in biomass, heterocyst number, and protein content and pathomorphological alterations.

  18. p-Chlorophenyl methyl sulfone

    Integrated Risk Information System (IRIS)

    p - Chlorophenyl methyl sulfone ; CASRN 98 - 57 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for No

  19. An Evaluation of a Teat Dip with Dodecyl Benzene Sulfonic Acid in Preventing Bovine Mammary Gland Infection from Experimental Exposure to Streptococcus agalactiae and Staphylococcus aureus

    PubMed Central

    Barnum, D. A.; Johnson, R. E.; Brooks, B. W.

    1982-01-01

    The effectiveness of a teat dip with dodecyl benzene sulfonic acid (1.94%) for the prevention of intramammary infections was determined in cows experimentally challenged with Streptococcus agalactiae and Staphylococcus aureus. The infection rates with Streptococcus agalactiae and Staphylococcus aureus were 62.5% and 75% in undipped quarters, 12.5% and 21.5% in dipped quarters with a reduction rate of 80% and 71% respectively. The significance of some findings in relation to mastitis control are discussed. PMID:17422110

  20. Structure proof and synthesis of kotalanol and de-O-sulfonated kotalanol, glycosidase inhibitors isolated from an herbal remedy for the treatment of type-2 diabetes.

    PubMed

    Jayakanthan, Kumarasamy; Mohan, Sankar; Pinto, B Mario

    2009-04-22

    Kotalanol and de-O-sulfonated-kotalanol are the most active principles in the aqueous extracts of Salacia reticulata which are traditionally used in India, Sri Lanka, and Thailand for the treatment of diabetes. We report here the exact stereochemical structures of these two compounds by synthesis and comparison of their physical data to those of the corresponding natural compounds. The candidate structures were based on our recent report on the synthesis of analogues and also the structure-activity relationship studies of lower homologues. The initial synthetic strategy relied on the selective nucleophilic attack of p-methoxybenzyl (PMB)-protected 4-thio-D-arabinitol at the least hindered carbon atom of two different, selectively protected 1,3-cyclic sulfates to afford the sulfonium sulfates. The protecting groups consisted of a methylene acetal, in the form of a seven-membered ring, and benzyl ethers. Deprotection of the adducts yielded the sulfonium ions but also resulted in de-O-sulfonation. Comparison of the physical data of the two adducts to those reported for de-O-sulfonated natural kotalanol yielded the elusive structure of kotalanol by inference. The side chain of this compound was determined to be another naturally occurring heptitol, d-perseitol (d-glycero-d-galacto-heptitol) with a sulfonyloxy group at the C-5 position. The synthesis of kotalanol itself was then achieved by coupling PMB-protected 4-thio-d-arabinitol with a cyclic sulfate that was synthesized from the naturally occurring d-perseitol. The work establishes unambiguously the structures of two natural products, namely, kotalanol and de-O-sulfonated kotalanol. PMID:19331410

  1. Efficacy of two acidified chlorite postmilking teat disinfectants with sodium dodecylbenzene sulfonic acid on prevention of contagious mastitis using an experimental challenge protocol.

    PubMed

    Oura, L Y; Fox, L K; Warf, C C; Kempt, G K

    2002-01-01

    Two acidified sodium chlorite postmilking teat disinfectants were evaluated for efficacy against Staphylococcus aureus and Streptococcus agalactiae by using National Mastitis Council experimental challenge procedures. The effect of these teat dips on teat skin and teat end condition was also determined. Both dips contained 0.32% sodium chlorite, 1.32% lactic, and 2.5% glycerin. Dips differed in the amount of sodium dodecylbenzene sulfonic acid (0.53 or 0.27%) added as a surfactant. Both dips significantly reduced new intramammary infection (IMI) rates compared with undipped controls. The dip containing 0.53% dodecylbenzene sulfonic acid reduced new IMI by Staph. aureus by 72% and Strep. agalactiae by 75%. The dip containing 0.27% dodecylbenzene sulfonic acid reduced new IMI by Staph. aureus by 100% and by Strep. agalactiae by 88%. Changes in teat skin and teat end condition for treatment and control groups varied in parallel over time. Teats treated with either teat dip had higher mean teat skin and teat end scores than control teats at some weeks. However, teat skin and teat end condition did not tend to change from the start to the completion of the trial. Application of the two new postmilking teat dips was effective in reducing new IMI from contagious mastitis pathogens. (Key words: teat dip, contagious mastitis, chlorous acid) PMID:11860118

  2. Chemical and Mechanical Degradation of Sulfonated Poly(sulfone) Membranes in Vanadium Redox Flow Batteries

    SciTech Connect

    Kim, Soowhan; Tighe, Timothy B.; Schwenzer, Birgit; Yan, Jingling; Zhang, Jianlu; Liu, Jun; Yang, Zhenguo; Hickner, Michael A.

    2011-10-01

    A sulfonated poly(sulfone) (S-Radel{reg_sign}) membrane with high proton conductivity and low vanadium ion diffusion showed high initial performance in a vanadium redox flow battery (VRFB) but suffered damage during charge/discharge cycling. The S-Radel membrane had different degradation behaviors in flow cell cycling and ex-situ vanadium ion immersion tests. The S-Radel membrane immersed in V5+ solution cracked into small pieces, but in the VRFB cell, the membrane underwent internal delamination preferentially on the side of the membrane that faced the positive electrode. A vanadium-rich interface was observed near the membrane surface that experienced delamination and Raman spectroscopic analysis of the surfaces of the membrane indicated a slightly depressed 1026 cm-1 band corresponding to the sulfonate SO2 stretch for the degraded surface. Even though the S-Radel membrane underwent severe mechanical damage during the flow cell cycling, significant chemical degradation was not obvious from the spectroscopic analyses. For the VRFB containing an S-Radel membrane, an increase in membrane resistance caused an abnormal voltage depression during the discharge cycle. The reversible increase in membrane resistance and severe mechanical degradation of the membrane during cycling may be attributed repeated formation and dissolution of particles inside the membrane. The mechanical stresses imposed by the particles coupled with a small amount of chemical degradation of the polymer by V5+, are likely degradation mechanisms of the S-Radel membrane in VRFBs under high state-of-charge conditions.

  3. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., polyamine condensate. 721.6220 Section 721.6220 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  4. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., polyamine condensate. 721.6220 Section 721.6220 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  5. 40 CFR 721.6220 - Aryl sulfonate of a fatty acid mixture, polyamine condensate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., polyamine condensate. 721.6220 Section 721.6220 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6220 Aryl sulfonate of a fatty acid mixture, polyamine condensate. (a... generically as an aryl sulfonate of a fatty acid mixture, polyamine condensate (PMN P-91-584) is subject...

  6. Water-soluble sulfonated hyperbranched poly(arylene oxindole) catalysts as functional biomimics of cellulases.

    PubMed

    Yu, Feng; Smet, Mario; Dehaen, Wim; Sels, Bert F

    2016-02-14

    A new polymer acid catalyst, sulfonated hyperbranched poly(arylene oxindole), 5-OH-SHPAO, was prepared for selective cellulose hydrolysis. Its superior catalysis, showing high glucose selectivity at almost full cellulose conversion, is attributed to the presence of an hydroxyl group next to the sulfonic acid, therefore mimicking the separate acid-base pair in the cellulase active site. PMID:26759837

  7. Characterization of sulfonated silica nanocomposite electrolyte membranes for fuel cell.

    PubMed

    Kim, Deuk-Ju; Nam, Sang-Yong

    2014-12-01

    Sulfonated poly(arylene ether sulfone) (SPAES) and sulfonated silica (silica-SO3H) prepared via sol-gel reaction are used as an organic polymer matrix and inorganic nanoparticles. The contents of the silica-SO3H particles in the composite membranes are controlled at 0.5, 1, 2, 3 and 5 wt.% in order to evaluate the appropriate content for high proton conductivity. Randomly dispersed silica particles are obtained from all composite membranes as a result of the hydrophilic domains in the polymer and silica-SO3H. In this study, the optimum silica-SO3H content for high proton conductivity is 3 wt.% in fully hydrated conditions and 0.5 wt.% in low humidity conditions. PMID:25970990

  8. p-Sulfonic Acid Calix[4]arene as an Efficient Catalyst for One-Pot Synthesis of Pharmaceutically Significant Coumarin Derivatives under Solvent-Free Condition

    PubMed Central

    Tashakkorian, Hamed; Lakouraj, Moslem Mansour; Rouhi, Mona

    2015-01-01

    One-pot and efficient protocol for preparation of some potent pharmaceutically valuable coumarin derivatives under solvent-free condition via direct coupling using biologically nontoxic organocatalyst, calix[4]arene tetrasulfonic acid (CSA), was introduced. Calix[4]arene sulfonic acid has been incorporated lately as a magnificent and recyclable organocatalyst for the synthesis of some organic compounds. Nontoxicity, solvent-free conditions, good-to-excellent yields for pharmaceutically significant structures, and especially ease of catalyst recovery make this procedure valuable and environmentally benign. PMID:26798517

  9. Sulfonated polysulfone battery membrane for use in corrosive environments

    DOEpatents

    Arnold, Jr., Charles; Assink, Roger

    1987-01-01

    For batteries containing strong oxidizing electrolyte and a membrane separating two electrolyte solutions, e.g., a zinc ferricyanide battery, an improved membrane is provided comprising an oxidative resistant, conductive, ion-selective membrane fabricated from a catenated aromatic polymer having an absence of tertiary hydrogens, e.g., a sulfonated polysulfone.

  10. Copolymers of fluorinated polydienes and sulfonated polystyrene

    DOEpatents

    Mays, Jimmy W.; Gido, Samuel P.; Huang, Tianzi; Hong, Kunlun

    2009-11-17

    Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

  11. Kinetics of sulfonation of amines of the benzene series with sulfur trioxide

    SciTech Connect

    Khelevin, R.N.

    1988-08-20

    The sulfonation of amines of the benzene series with sulfur trioxide in dichloroethane is described by a third-order kinetic equation for an irreversible process, and first order is observed with respect to the compound being sulfonated and second with respect to the sulfur trioxide. The unprotonated molecules of the amines undergo sulfonation, and this leads to the production of the para-aminosulfonic acids with small amounts of the ortho isomers. The reaction mechanism involves electrophilic reaction of the unprotonated amine molecule with the sulfur trioxide dimer S/sub 2/O/sub 6/ and subsequent dissociation of the obtained pyrosulfonate with the production of the amino sulfonic acid and sulfur trioxide. Sulfonation with sulfur trioxide is of interest in connection with the high rate and degree of completion of the reaction and the absence of energy expenditures.

  12. Anaerobic degradation of linear alkylbenzene sulfonate.

    PubMed

    Mogensen, Anders S; Haagensen, Frank; Ahring, Birgitte K

    2003-04-01

    Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C12 LAS), which show that C12 LAS was biodegradable under methanogenic conditions. Sorption of C12 LAS on sewage sludge was described with a Freundlich isotherm. The C12 LAS sorption was determined with different concentrations of total solids (TS). In the semi-continuously stirred tank reactor, 18% of the added C12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation under thermophilic conditions was 37% with LAS as sole carbon source. Benzaldehyde was produced in the UASB reactor during LAS transformation. PMID:12685701

  13. Highly elevated levels of perfluorooctane sulfonate and other perfluorinated acids found in biota and surface water downstream of an international airport, Hamilton, Ontario, Canada.

    PubMed

    de Solla, S R; De Silva, A O; Letcher, R J

    2012-02-01

    Per- and poly-fluorinated compounds (PFCs), which include perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs) and various precursors, are used in a wide variety of industrial, commercial and domestic products. This includes aqueous film forming foam (AFFF), which is used by military and commercial airports as fire suppressants. In a preliminary assessment prior to this study, very high concentrations (>1 ppm wet weight) of the PFSA, perfluorooctane sulfonate (PFOS), were discovered in the plasma of snapping turtles (Chelydra serpentina) collected in 2008 from Lake Niapenco in southern Ontario, Canada. We presently report on a suite of C(6) to C(15) PFCAs, C(4), C(6), C(8) and C(10) PFSAs, several PFC precursors (e.g. perfluorooctane sulfonamide, PFOSA), and a cyclic perfluorinated acid used in aircraft hydraulic fluid, perfluoroethylcyclohexane sulfonate (PFECHS) in surface water from the Welland River and Lake Niapenco, downstream of the John C. Munro International Airport, Hamilton, Ontario, Canada. Amphipods, shrimp, and water were sampled from the Welland River and Lake Niapenco, as well as local references. The same suite of PFCs in turtle plasma from Lake Niapenco was compared to those from other southern Ontario sites. PFOS dominated the sum PFCs in all substrates (e.g., >99% in plasma of turtles downstream the Hamilton Airport, and 72.1 to 94.1% at all other sites). PFOS averaged 2223(±247.1SE) ng/g in turtle plasma from Lake Niapenco, and ranged from 9.0 to 171.4 elsewhere. Mean PFOS in amphipods and in water were 518.1(±83.8)ng/g and 130.3(±43.6) ng/L downstream of the airport, and 19.1(±2.7) ng/g and 6.8(±0.5) ng/L at reference sites, respectively. Concentrations of selected PFCs declined with distance downstream from the airport. Although there was no known spill event or publicly reported use of AFFF associated with a fire event at the Hamilton airport, the airport is a likely major source of PFC contamination in the Welland River. PMID

  14. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss)

    EPA Science Inventory

    Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma, and either urine or expired water. The data were then an...

  15. EVALUATION OF PERFLUOROOCTANE SULFONATE IN THE RAT BRAIN

    EPA Science Inventory

    Perfluorooctane Sulfonate (PFOS) is an environmentally persistent chemical that has been detected in humans and wildlife. PFOS is primarily distributed in liver and blood. The current study evaluated the level of PFOS in the adult and neonatal rat brain and determined whether t...

  16. Absorption and distribution of perfluorooctane sulfonate (PFOS) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is found in biosolids, and the application of these biosolids to pastures has raised concerns about human exposure through the accumulation of PFOS in edible tissues of these animals. The United States Department of Agriculture (USDA) h...

  17. Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

    DOEpatents

    Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

    2010-10-19

    An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

  18. Direct catalytic olefination of alcohols with sulfones.

    PubMed

    Srimani, Dipankar; Leitus, Gregory; Ben-David, Yehoshoa; Milstein, David

    2014-10-01

    The synthesis of terminal, as well as internal, olefins was achieved by the one-step olefination of alcohols with sulfones catalyzed by a ruthenium pincer complex. Furthermore, performing the reaction with dimethyl sulfone under mild hydrogen pressure provides a direct route for the replacement of alcohol hydroxy groups by methyl groups in one step. PMID:25163718

  19. Use of amine neutralized sulfonated polystyrenes for particle flocculation

    SciTech Connect

    Mintz, D.J.; Peiffer, D.G.; Thaler, W.A.; Duvdevani, I.

    1987-10-20

    A process is described for flocculating solid fines selected from the group consisting of coke films, catalyst fines, synthetic fuel fines, coal fines, and shale fines from a solution comprising the solid fines and an organic liquid which comprises the steps of: (a) adding with mixing about 5 to about 10,000 ppm of the water insoluble unneutralized or neutralized sulfonated polystyrene to the solution wherein the sulfonated polystyrene is dissolved in a dissolving organic liquid at a concentration level of about 0.01 to about 20 weight percent, and has about 0.5 to about 100 mole percent of sulfonate groups; and (b) heating at about 25/sup 0/C to about 350/sup 0/C for about 1 to about 45 minutes the mixture of the solution and the unneutralized or neutralized polystyrene wherein the sulfonated polystrene is absorbed on the surface of the solid fines, and the solid fines collide to form agglomerates which precipitate out of the solution.

  20. Hydrogen-bonding patterns in pyrimethaminium pyridine-3-sulfonate

    PubMed Central

    Nirmalram, Jeyaraman Selvaraj; Thomas Muthiah, Packianathan

    2010-01-01

    In the asymmetric unit of the title salt [systematic name: 2,4-diamino-5-(4-chloro­phen­yl)-6-ethyl­pyrimidin-1-ium pyri­dine-3-sulfonate], C12H14N4Cl+·C5H4NSO3 −, there are two independent pyrimethaminium cations and two 3-pyridine sulfonate anions. Each sulfonate group inter­acts with the corresponding protonated pyrimidine ring through two N—H⋯O hydrogen bonds, forming a cyclic hydrogen-bonded bimolecular R 2 2(8) motif. Even though the primary mode of association is the same, the next higher level of supra­molecular architectures are different due to different hydrogen-bonded networks. In one of the independent molecules in the asymmetric unit, the pyrimethamine cation is paired centrosymmetrically through N—H⋯N hydrogen bonds, generating an R 2 2(8) ring motif. In the other molecule, the pyrimethamine cation does not form any base pairs; instead it forms hydrogen bonds with the 3-pyridine sulfonate anion. The structure is further stabilized by C—H⋯O, C—H⋯N and π–π stacking [centroid–centroid distance = 3.9465 (13) Å] inter­actions. PMID:21588411

  1. Sulfone-Containing Methacrylate Homopolymers: Wetting and Thermal Properties.

    PubMed

    Fujii, Shota; McCarthy, Thomas J

    2016-01-26

    Although the sulfonyl functional group has a large dipole moment and compounds containing them (sulfones) have correspondingly high dielectric constants, this chemical structure has been neglected for use as a functional group to render surfaces hydrophilic. We have prepared three methacrylate polymers containing side chains capped with sulfolane, methylsulfone, and ethylsulfone functionality. The sulfolane-containing polymer exhibits an unusually high glass transition temperature (Tg = 188°C) for a methacrylate polymer and slightly different thermal degradation behavior than the other two sulfone-containing polymers, likely due to the bulky structure of the sulfolane group in the polymer side chain. At macroscopic polymer film/water interfaces, the sulfone-containing side chains exposed to the interface impart hydrophilic properties as assessed by contact angle analysis. The hydrophilicities of sulfolane and methylsulfone surfaces are similar, and greater than the ethylsulfone surface. Although the chemical compositions of the sulfolane and ethylsulfone polymers are almost identical, the five-membered ring structure of sulfolane allows the sulfonyl moiety to be exposed at the interface in a manner similar to that of the methylsulfone polymer. The sulfonyl group at the ethylsulfone polymer/water interface is slightly masked by the ethyl group. Interestingly, the sulfolane surface displays a higher affinity to methylene iodide and n-hexadecane probe fluids compared to the other sulfone surfaces, suggesting that the five-membered ring structure of the sulfolane moiety can orient in a manner that shelters the sulfonyl group at hydrophobic interfaces. PMID:26716766

  2. Novel Ordered Mesoporous Carbon Based Sulfonic Acid as an Efficient Catalyst in the Selective Dehydration of Fructose into 5-HMF: the Role of Solvent and Surface Chemistry.

    PubMed

    Karimi, Babak; Mirzaei, Hamid M; Behzadnia, Hesam; Vali, Hojatollah

    2015-09-01

    Novel ionic liquid derived ordered mesoporous carbons functionalized with sulfonic acid groups IOMC-ArSO3H and GIOMC-ArSO3H were prepared, characterized, and examined in the dehydration reaction of fructose into 5-hydroxymethylfurfural (5-HMF) both in aqueous and nonaqueous systems. To study and correlate the surface properties of these carbocatalysts and some other SBA-15 typed solid acids with 5-HMF yield, hydrophilicity index (H-index) were employed in the fructose dehydration. Our study systematically declared that almost a criterion may be expected for application of solid acids in which by increasing H-index value up to 0.8 the HMF yield enhances accordingly. More increase in H-index up to 1.3 did not change the HMF yield profoundly. Although, it has been shown that the catalyst with larger H-index (∼1.3) resulted in higher activity both in aqueous and 2-propanol systems, during the recycling process deactivation occurs because of more water uptake and the catalysts with optimum amount of H-index (∼0.8) is more robust in the dehydration of fructose. PMID:26259108

  3. Chlorine resistant desalination membranes based on directly sulfonated poly(arylene ether sulfone) copolymers

    DOEpatents

    McGrath, James E.; Park, Ho Bum; Freeman, Benny D.

    2011-10-04

    The present invention provides a membrane, kit, and method of making a hydrophilic-hydrophobic random copolymer membrane. The hydrophilic-hydrophobic random copolymer membrane includes a hydrophilic-hydrophobic random copolymer. The hydrophilic-hydrophobic random copolymer includes one or more hydrophilic monomers having a sulfonated polyarylsulfone monomer and a second monomer and one or more hydrophobic monomers having a non-sulfonated third monomer and a fourth monomer. The sulfonated polyarylsulfone monomer introduces a sulfonate into the hydrophilic-hydrophobic random copolymer prior to polymerization.

  4. Detergent induces the formation of IgG aggregates: a multi-methodological approach.

    PubMed

    Amani, Samreen; Nasim, Faisal; Khan, Taqi Ahmed; Fazili, Naveed Ahmad; Furkan, Mohammad; Bhat, Imtiyaz Ahmad; Khan, Javed Masood; Khan, Rizwan Hasan; Naeem, Aabgeena

    2014-01-01

    Role of micellar environment created by Triton X-100 (TX-100) and CHAPSO on protein conformation using IgG as a model system has been studied in this paper. A substantial amount of secondary structure with the reduction in constant tertiary contacts was obtained in both bovine and human IgG in the presence of 0.12 mM TX-100 where as 6 and 8 mM CHAPSO concentration was required for this type of secondary structure. Further addition of either of the detergents result in the induction of α-helix in both the IgGs as evident by helix specific peaks in the amide I region of FTIR and circular dichroism spectra. Tryptophan and 8-anilino-1-naphthalene-sulphonic acid (ANS) fluorescence confirmed changes in protein conformation upon addition of detergents. Maximum ANS binding at 0.12 mM TX-100 in both while 6 and 8 mM CHAPSO in bovine and human IgG respectively, indicate a compact ''molten-globule''-like conformation. An increase addition of these detergents results in the burial of hydrophobic patches of both IgG owing to aggregation. Presence of aggregates at 0.2 and 0.16 mM TX-100 and 8 and 9 mM CHAPSO, for bovine and human IgG respectively, was further confirmed by reduction in ANS fluorescence, dynamic light scattering study, thioflavin T fluorescence and congo red absorbance. PMID:24184618

  5. Morphology and Proton Transport in Sulfonated Block Copolymer and Mesoporous Polymer Electrolyte Membranes

    NASA Astrophysics Data System (ADS)

    Chen, Chelsea; Wong, David; Beers, Keith; Balsara, Nitash

    2013-03-01

    In an effort to understand the fundamentals of proton transport in polymer electrolyte membranes (PEMs), we have developed a series of poly(styrene-b-ethylene-b-styrene) (SES) membranes. The SES membranes were subsequently sulfonated to yield proton conducting S-SES membranes. We examine the effects of sulfonation level, temperature and thermal history on the morphology of S-SES membranes in both dry and hydrated states. The effects of these parameters on water uptake and proton transport characteristics of the membranes are also examined. Furthermore, building upon the strategy we deployed in sulfonating the SES membranes, we fabricated mesoporous S-SES membranes, with pores lined up with the proton conducting channels. These membranes have three distinct phases: structural block, proton-conducting block, and void. We examine the effects of pore size, domain structure and sulfonation level on water uptake and proton conductivity of the mesoporous PEMs at different temperatures. This work is funded by Department of Energy.

  6. Continuous separation of serum proteins using a stirred cell charged with carboxylated and sulfonated microspheres.

    PubMed

    Lee, J H; Yoon, J Y; Kim, W S

    1998-01-01

    We contrived a new separation system using a stirred cell charged with uncoupled microsphere similar to the chromatographic separation. Microspheres, carboxylated PS/PMAA and sulfonated PS/PNaSS, were prepared by emulsifier-free emulsion polymerization. To complement the submicron size weakness and the absence of ligands, we employed the latex form, the dispersion of microsphere, and took advantage of interaction relationships between proteins and microspheres. Adsorption isotherm is contemplated to investigate continuous separation behaviours of serum proteins. Selectivity of separation is in the following order: PS/PNaSS-2.0 (high sulfonated) < PS/PNaSS-0.3 (low sulfonated) < PS/PMAA-0.5 (low carboxylated). Unlike previous works on batch separation, not only the adsorbed amount in equilibrium (Cm), but also adsorption coefficient (K), played an important role in continuous separation. Functional groups (carboxyl and sulfonate), induced from the co-monomer, also affected the adsorption behaviours. PMID:9861492

  7. Effective catalytic conversion of cellulose into high yields of methyl glucosides over sulfonated carbon based catalyst.

    PubMed

    Dora, Sambha; Bhaskar, Thallada; Singh, Rawel; Naik, Desavath Viswanatha; Adhikari, Dilip Kumar

    2012-09-01

    An amorphous carbon based catalyst was prepared by sulfonation of the bio-char obtained from fast pyrolysis (N(2) atm; ≈ 550°C) of biomass. The sulfonated carbon catalyst contained high acidity of 6.28 mmol/g as determined by temperature programmed desorption of ammonia of sulfonated carbon catalyst and exhibited high catalytic performance for the hydrolysis of cellulose. Amorphous carbon based catalyst containing -SO(3)H groups was successfully tested and the complete conversion of cellulose in methanol at moderate temperatures with high yields ca. ≥ 90% of α, β-methyl glucosides in short reaction times was achieved. The methyl glucosides formed in methanol are more stable for further conversion than the products formed in water. The carbon catalyst was demonstrated to be stable for five cycles with slight loss in catalytic activity. The utilization of bio-char as a sulfonated carbon catalyst provides a green and efficient process for cellulose conversion. PMID:22776237

  8. Sulfonic acids: catalysts for the liquid-liquid extraction of metals

    SciTech Connect

    Osseo-Asare, K.; Keeney, M.E.

    1980-05-01

    Three sulfonic acid extractants, dinonylnaphthalene sulfonic acid (HDNNS), didodecylnaphthalene sulfonic acid (HDDNS) and di-(2-ethyl-hexyl) sodium sulfosuccinate (Aerosol OT, AOT) are compared as to their effects on the extraction of nickel with LIX63. The acidic extractants interact synergistically with the oxime. Interfacial tension results are presented which demonstrate that the sulfonates form reversed micelles in non-polar organic solvents. It is proposed that the reversed micelles catalyze the extraction by specific solubilization of both the metal and the extractant, resulting in an increase in the interfacial concentration of the reacting species. The ability of LIX63 to chelate with nickel without deprotonating permits the synergism to occur at low pH.

  9. Electric current-producing device having sulfone-based electrolyte

    DOEpatents

    Angell, Charles Austen; Sun, Xiao-Guang

    2010-11-16

    Electrolytic solvents and applications of such solvents including electric current-producing devices. For example, a solvent can include a sulfone compound of R1--SO2--R2, with R1 being an alkyl group and R2 a partially oxygenated alkyl group, to exhibit high chemical and thermal stability and high oxidation resistance. For another example, a battery can include, between an anode and a cathode, an electrolyte which includes ionic electrolyte salts and a non-aqueous electrolyte solvent which includes a non-symmetrical, non-cyclic sulfone. The sulfone has a formula of R1--SO2--R2, wherein R1 is a linear or branched alkyl or partially or fully fluorinated linear or branched alkyl group having 1 to 7 carbon atoms, and R2 is a linear or branched or partially or fully fluorinated linear or branched oxygen containing alkyl group having 1 to 7 carbon atoms. The electrolyte can include an electrolyte co-solvent and an electrolyte additive for protective layer formation.

  10. Effect of additives on the performance and morphology of sulfonated copoly (phthalazinone biphenyl ether sulfone) composite nanofiltration membranes☆

    NASA Astrophysics Data System (ADS)

    Guan, Shanshan; Zhang, Shouhai; Liu, Peng; Zhang, Guozhen; Jian, Xigao

    2014-03-01

    Sulfonated copoly (phthalazinone biphenyl ether sulfone) (SPPBES) composite nanofiltration membranes were fabricated by adding low molecular weight additives into SPPBES coating solutions during a dip coating process. Three selected additives: glycol, glycerol and hydroquinone were used in this work. The effect of additives on the membrane performance was studied and discussed in terms of rejection and permeation flux. Among all the composite membranes, the membrane prepared with glycol as an additive achieved the highest Na2SO4 rejection, and the membrane fabricated with glycerol as an additive exhibited the highest flux. The salts rejection of SPPBES composite membranes increased in the following order MgCl2 < NaCl ≤ MgSO4 < Na2SO4. The morphologies of the SPPBES composite membranes were characterized by SEM, it was found that the membrane prepared with hydroquinone showed a rough membrane surface. Composite membrane fabricated with glycol or glycerol as the additive showed very good chemical stability.

  11. Radiation-induced crosslinking of poly(styrene-butadiene-styrene) block copolymers and their sulfonation

    NASA Astrophysics Data System (ADS)

    Lee, Sun-Young; Song, Ju-Myung; Sohn, Joon-Yong; Shul, Yong-Gun; Shin, Junhwa

    2013-12-01

    Several crosslinked poly(styrene-butadiene-styrene) (c-SBS) block copolymer films were prepared using a gamma ray or electron beam with various irradiation doses and the prepared c-SBS film was then subjected to sulfonation using a chlorosulfonic acid (CSA) solution to introduce a sulfonic acid group. To estimate the degree of crosslinking, the gel fractions and FT-IR spectra of the c-SBS films were used and the results indicate that the degree of crosslinking is increased with an increase in the radiation dose. The surface morphology and mechanical property of the c-SBS films were observed using SEM and UTM instruments, respectively. The sulfonated c-SBS films were investigated by measuring the ion exchange capacity (IEC) and by observing the cross-sectional distribution patterns of sulfonic acid group using an SEM-EDX instrument. The IEC and SEM-EDX studies indicate that the sulfonated c-SBS membranes can be successfully prepared through the radiation crosslinking of the SBS film and the subsequent sulfonation with a diluted CSA solution.

  12. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

    PubMed Central

    Das, Gautam; Yoon, Hyon Hee

    2015-01-01

    An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm−2·mM−1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. PMID:26346240

  13. Sulfonated polyaniline, a conducting polymer electrode for ion transfer batteries

    SciTech Connect

    Barbero, C.; Miras, M.C.; Koetz, R.; Haas, O.

    1994-12-31

    Sulfonated polyaniline (SPAN) was synthesized by sulfonation of polyaniline base with f6ming sulfuric acid. The polymer films were characterized by XPS, FFIR and UV-vis-NIR. XPS in combination with FTIR shows that the preparation procedure leads to a ca. 47% sulfonation of an otherwise unchanged polyaniline backbone. Electrodes modified with SPAN films exhibited two redox steps in aqueous as well as in nonaqueous electrolytes. Probe Beam Deflection and Quartz Crystal Microbalance were used to study the ion exchange mechanism. Protons are predominantly expelled during the first and second oxidation steps in acidic aqueous solution, accompanied by a counterflux of solvent. In nonaqueous electrolyte, expulsion of cations seems to be the dominant flux during SPAN oxidation, while solvent counterflux plays a significant role. The specific charge of SPAN films was found to be ca. 37 Ah/kg in aqueous solution (only first redox process used) and ca. 68 Ah/kg in nonaqueous media (both redox processes). Based on their experimental results, an estimation for a practical SPAN/Li battery would have 50% more specific energy than a PANI/Li one.

  14. Wear Reduction Effects of Ca Sulfonate on Coated Tools in Hobbing

    NASA Astrophysics Data System (ADS)

    Matsuoka, Hironori; Ono, Hajime; Tsuda, Yoshihiro

    This paper presents the influence of Ca sulfonate on tool life (flank wear), crater wear and finished surface roughness in hobbing. Experiments were carried out using two kinds of fully coated fly tools with TiN and (Al, Ti)N films respectively. As the results, when using the TiN fully coated tool, Ca sulfonate prolongs the tool life, and decreases the crater wear compared with the machine oil 23 as a base oil. With the (Al, Ti)N fully coated tool, an interesting result was obtained that the base oil containing no additives gives a longer tool life and a smaller crater wear than those obtained with Ca sulfonates added. It was suggested that the increase in the flank wear and the crater wear is caused by the chemical and/or the corrosive actions of Ca sulfonate, when Ca sulfonate was used for the (Al, Ti)N coated tool. Ca sulfonates improve the finished surface roughness for both coated tools.

  15. Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

    SciTech Connect

    Nath, Bhabesh Kumar; Khan, Aziz; Chutia, Joyanti

    2015-10-15

    Highlights: • Methyl methane sulfonate (MMS) is used as the sulfonating agent. • The proton conductivity of the membrane is found to be 0.141 S cm{sup −1}. • Power density of fuel cell with styrene/MMS membrane is 0.5 W cm{sup −2}. • The membrane exhibits thermal stability up to 140 °C. - Abstract: This work presents the introduction of an organic compound methyl methane sulfonate (MMS) for the first time in fabrication of polystyrene based proton exchange membrane (PEM) by plasma polymerization process. The membrane is fabricated by co-polymerizing styrene and MMS in capacitively coupled continuous RF plasma. The chemical composition of the plasma polymerized polymer membrane is investigated using Fourier Transform Infrared Spectroscopy which reveals the formation of composite structure of styrene and MMS. The surface morphology studied using AFM and SEM depicts the effect of higher partial pressure of MMS on surface topography of the membrane. The proton transport property of the membrane studied using electrochemical impedance spectroscopy shows the achievement of maximum proton conductivity of 0.141 S cm{sup −1} which is comparable to Nafion 117 membrane. Fuel cell performance test of the synthesized membrane shows a maximum power density of 500 mW cm{sup −2} and current density of 0.62 A cm{sup −2} at 0.6 V.

  16. Study of sulfonated polyether ether ketone with pendant lithiated fluorinated sulfonic groups as ion conductive binder in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Wei, Zengbin; Xue, Lixin; Nie, Feng; Sheng, Jianfang; Shi, Qianru; Zhao, Xiulan

    2014-06-01

    In an attempt to reduce the Li+ concentration polarization and electrolyte depletion from the electrode porous space, sulfonated polyether ether ketone with pendant lithiated fluorinated sulfonic groups (SPEEK-FSA-Li) is prepared and attempted as ionic conductivity binder. Sulfonated aromatic poly(ether ether ketone) exhibits strong adhesion and chemical stability, and lithiated fluorinated sulfonic side chains help to enhance the ionic conductivity and Li+ ion diffusion due to the charge delocalization over the sulfonic chain. The performances are evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, charge-discharge cycle testing, 180° peel testing, and compared with the cathode prepared with polyvinylidene fluoride binder. The electrode prepared with SPEEK-FSA-Li binder forms the relatively smaller resistances of both the SEI and the charge transfer of lithium ion transport. This is beneficial to lithium ion intercalation and de-intercalation of the cathode during discharging-charging, therefore the cell prepared with SPEEK-FSA-Li shows lower charge plateau potential and higher discharge plateau potential. Compared with PVDF, the electrode with ionic binder shows smaller decrease in capacity with the increasing of cycle rate. Meanwhile, adhesion strength of electrode prepared with SPEEK-FSA-Li is more than five times greater than that with PVDF.

  17. Simulation study of sulfonate cluster swelling in ionomers

    NASA Astrophysics Data System (ADS)

    Allahyarov, Elshad; Taylor, Philip L.; Löwen, Hartmut

    2009-12-01

    We have performed simulations to study how increasing humidity affects the structure of Nafion-like ionomers under conditions of low sulfonate concentration and low humidity. At the onset of membrane hydration, the clusters split into smaller parts. These subsequently swell, but then maintain constant the number of sulfonates per cluster. We find that the distribution of water in low-sulfonate membranes depends strongly on the sulfonate concentration. For a relatively low sulfonate concentration, nearly all the side-chain terminal groups are within cluster formations, and the average water loading per cluster matches the water content of membrane. However, for a relatively higher sulfonate concentration the water-to-sulfonate ratio becomes nonuniform. The clusters become wetter, while the intercluster bridges become drier. We note the formation of unusual shells of water-rich material that surround the sulfonate clusters.

  18. Ion Exchange Formation via Sulfonated Bicomponent Nonwovens

    NASA Astrophysics Data System (ADS)

    Stoughton, Hannah L.

    For many years ion exchange resins were used to: remove heavy metals from water, recover materials from wastewater, and eliminate harmful gases from the air. While use of these resin beads dominates the ion exchange industry, the beads have limitations that should be considered when decisions are made to employ them. For instance, officials must balance the inherent zero sum surface area and porosity of the materials. This series of studies investigates the use of bicomponent nonwovens as a base substrate for producing high surface area ion exchange materials for the removal of heavy metal ions. Functionalized materials were produced in a two-step process: (1) PET/PE spunbond bicomponent fibers were fractured completely, producing the high surface area nonwoven to be used as the base ion exchange material, and (2) the conditions for functionalizing the PET fibers of the nonwoven webs were investigated where an epoxy containing monomer was grafted to the surface followed by sulfonation of the monomer. The functionalization reactions of the PET fibers were monitored based on: weight gain, FTIR, TOF-SIMS, and SEM. Ion exchange properties were evaluated using titration and copper ion removal capacity from test solutions. The relationship between web structure and removal efficiency of the metal ions was defined through a comparison of the bicomponent and homocomponent nonwovens for copper ion removal efficiency. The investigation revealed that utilizing the high surface area, fractured bicomponent nonwoven ion exchange materials with capacities comparable to commercially available ion exchange resins could be produced.

  19. 40 CFR 721.10035 - Alkylbenzene sulfonate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylbenzene sulfonate (generic). 721... Substances § 721.10035 Alkylbenzene sulfonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate...

  20. 40 CFR 721.10035 - Alkylbenzene sulfonate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylbenzene sulfonate (generic). 721... Substances § 721.10035 Alkylbenzene sulfonate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkylbenzene sulfonate...

  1. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Trifluoromethane sulfonic acid. 173.395 Section 173... CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid... acid) may safely be used in the production of cocoa butter substitute from palm oil...

  2. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Trifluoromethane sulfonic acid. 173.395 Section... HUMAN CONSUMPTION Specific Usage Additives § 173.395 Trifluoromethane sulfonic acid. Trifluoromethane sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst...

  3. Toxicity of pyrolysis gases from polyether sulfone

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  4. Radiation synthesis of eco-friendly water reducing sulfonated starch/acrylic acid hydrogel designed for cement industry

    NASA Astrophysics Data System (ADS)

    Abd El-Rehim, H. A.; Hegazy, El-Sayed A.; Diaa, D. A.

    2013-04-01

    Starch was treated with chlorosulfonic acid to obtain sulfonated starch. Acrylic acid/sulfonated starch semi-interpenetrated network IPN of different compositions was prepared using ionizing radiation. Swelling of prepared IPNs at different environmental conditions was studied. The possible use of sulfonated starch/acrylic acid IPN as a water-retarding agent in the cement industry was investigated. ζ-potential measurements were used to determine the stability of the colloidal cement—SS/AA and cement -poly-naphthalene sulfonic acid (SNF) water retarding mixtures. Sulfonated starch/acrylic acid water-retarding property was influenced by hydrogel concentration and composition. Sulfonated starch/acrylic acid IPN admixture has a great effect on the cement initial setting time. Using 2% of SS/AA or SNF resulted in an increase in initial setting time by 2 and 1 h respectively, if compared with native cement initial setting time. The results showed that the synthetic commercial super-plasticizers could be replaced by an eco-friendly water-retarding sulfonated starch/acrylic acid IPN in the cement industry.

  5. Nitric Acid Dehydration Using Perfluoro Carboxylate and Mixed Sulfonate/Carboxylate Membranes

    SciTech Connect

    R.L. Ames

    2004-09-01

    Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, ''as received'' perfluoro carboxylate and similar sulfonate films. Small angle x-ray scattering analysis results suggested that the solution cast carboxylate films contained a small fraction of sulfonate terminated side-chains. Aqueous transport experimentation showed that permeate fluxes for both pure water and nitric acid were approximately two orders of magnitude smaller for the carboxylate solution cast membranes when compared to their sulfonate counterparts of similar thickness

  6. Characteristics of the uptake of 3,5,3'-triiodo-L-thyronine and L-thyroxine into red blood cells of rainbow trout (Oncorhynchus mykiss).

    PubMed

    McLeese, J M; Eales, J G

    1996-08-01

    The mechanisms of uptake of thyroid hormones (TH) 3,5,3'-triiodo-L-thyronine (T3) and L-thyroxine (T4) by trout red blood cells (RBC) were characterized by coincubating washed RBC with [125I]T3 or [125I]T4 and a variety of inhibitors and potentially competing amino acids and TH analogues. Nonsaturable uptake of both TH was unaffected by almost all agents tested, consistent with a diffusion process. Saturable T3 uptake was unaffected by a major (80%) cyanide- and iodoacetate-induced reduction in RBC nucleotide triphosphate content or by inhibitors of Na+ transport, but was depressed by (i) inhibitors of protein binding (bromosulfophthalein, 8-anilino-1-naphthalene sulfonic acid, phloretin, and 5,5'-diphenylhydantoin, (ii) sulfhydryl blockers (p-hydroxy-mercuribenzoate and N-ethylmaleimide), (iii) endocytotic inhibitors (chloroquine, colchicine, and monodansylcadaverine), (iv) tryptophan and phenylalanine, and (v) certain TH analogues, particularly 3,3',5'-triiodo-L-thyronine (reverse T3). In contrast, saturable T4 uptake was depressed only by inhibitors or protein binding. Cross-competition between T3 and T4 for transport occurred only at highly pharmacologic TH levels. We conclude that T3 and T4 are transported into trout RBC by two separate systems. The relatively slow T4 uptake depends on binding to certain proteins. The much more rapid T3 uptake depends on protein binding, but is Na(+)-independent, and involves a system comparable to the T-system of aromatic amino acid transport. However, participation od receptor-mediated endocytosis cannot be excluded. PMID:8812373

  7. Hydrocarbon and partially fluorinated sulfonated copolymer blends as functional membranes for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Arnett, Natalie Y.; Harrison, William L.; Badami, Anand S.; Roy, Abhishek; Lane, Ozma; Cromer, Frank; Dong, Limin; McGrath, James E.

    Polymer blending is recognized as a valuable technique used to modify and improve the mechanical, thermal, and surface properties of two different polymers or copolymers. This paper investigated the solution properties and membrane properties of a biphenol-based disulfonated poly (arylene ether sulfone) random copolymer (BPS-35) with hexafluoroisopropylidene bisphenol based sulfonated poly (arylene ether sulfone) copolymers (6FSH) and an unsulfonated biphenol-based poly (arylene ether sulfone)s. The development of blended membranes with desirable surface characteristics, reduced water swelling and similar proton conductivity is presented. Polymer blends were prepared both in the sodium salt and acid forms from dimethylacetamide (DMAc). Water uptake, specific conductivity, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and contact angles were used to characterize the blended films. Surface enrichment of the fluorinated component is illustrated by an significant increase in the water-surface contact angle was observed when 10 wt.% 6FBPA-00 (106°) was added to BPS 35 (80°). Water weight gain was reduced by a factor of 2.

  8. Sulfonated nanoporous colloidal films and membranes

    NASA Astrophysics Data System (ADS)

    Smith, Joanna Jane

    The objective of this thesis is to describe the preparation and investigation of a new class of proton-conducting membrane materials, namely, nanoporous colloidal membranes whose proton conductivity results from the nanopore surface modification with organic molecules carrying acid functionalities. Both the proton transport and ion transport were studied in nanoporous silica colloidal crystals that were surface modified with sulfonic groups. First, the transport of ions was studied through sulfonated silica colloidal films that were supported on platinum electrodes using cyclic voltammetry. The surface of self-assembled nanoporous silica colloidal crystalline films was sulfonated using 1,3-propanesultone. We found that the flux of anions through the sulfonated colloidal films is reduced, while the flux of cations is increased, compared to the unmodified colloidal films. Second, the proton transport in free-standing assemblies of surface-sulfonated silica nanospheres, either randomly packed or self-assembled into a close-packed arrangement, were studied. It was demonstrated that colloidal assemblies prepared using surface-sulfonated silica nanospheres posses proton conductivity that depends on the ordering of the material, temperature and relative humidity. Based on the comparison between the close-packed and disordered assemblies made of the same spheres, we conclude that the increase in structural organization of the self-assembled colloidal materials leads to increased proton conductivity and better water retention. Next free-standing colloidal membranes with a relatively large area and no mechanical defects were prepared by sintering silica colloidal films. The sintered membranes were then surface rehydroxylated, which restores the surface silanol groups, and then can be chemically modified. Finally, sintered self-assembled nanoporous silica colloidal crystals were modified with poly(sulfopropyl-methacrylate) (pSPM) and poly(stryrenesulfonic acid) (pSSA) brushes

  9. Demonstration of proof of mechanism and pharmacokinetics and pharmacodynamic relationship with 4'-cyano-biphenyl-4-sulfonic acid (6-amino-pyridin-2-yl)-amide (PF-915275), an inhibitor of 11 -hydroxysteroid dehydrogenase type 1, in cynomolgus monkeys.

    PubMed

    Bhat, B Ganesh; Hosea, Natilie; Fanjul, Andrea; Herrera, Jocelyn; Chapman, Justin; Thalacker, Fred; Stewart, Paul M; Rejto, Paul A

    2008-01-01

    Glucocorticoids, through activation of the glucocorticoid receptor (GR), regulate hepatic gluconeogenesis. Elevated hepatic expression and activity of 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) play a key role in ligand-induced activation of the GR through the production of cortisol. Evidence from genetically modified mice suggests that inhibition of 11betaHSD1 might be a therapeutic approach to treat the metabolic syndrome. We have identified a potent 11betaHSD1 inhibitor, 4'-cyano-biphenyl-4-sulfonic acid (6-amino-pyridin-2-yl)-amide (PF-915275), that is selective for the primate and human enzymes. The objective of this study was to demonstrate target inhibition with PF-915275 and to quantify the relationship between target inhibition and drug exposure in monkeys. We characterized the ability of PF-915275 to inhibit the conversion of prednisone, a synthetic cortisone analog that can be distinguished from the endogenous substrate cortisone, enabling a direct measure of substrate to product conversion without the complication of feedback. Adult cynomolgus monkeys were administered either vehicle or various doses of PF-915275 followed by a 10-mg/kg dose of prednisone. Prednisone conversion to prednisolone and the concentrations of PF-915275 were measured by liquid chromatography/tandem mass spectrometry. PF-915275 dose-dependently inhibited 11betaHSD1-mediated conversion of prednisone to prednisolone, with a maximum of 87% inhibition at a 3-mg/kg dose. An exposure-response relationship was demonstrated, with an estimated EC(50) of 391 nM (total) and 17 nM (free). Insulin levels were also reduced in a dose-related manner. These results should enable the development of a biomarker for evaluating target modulation in humans that will aid in identifying 11betaHSD1 inhibitors to treat diabetes and other related metabolic diseases. PMID:17921190

  10. Highly branched sulfonated poly(fluorenyl ether ketone sulfone)s membrane for energy efficient vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Yin, Bibo; Li, Zhaohua; Dai, Wenjing; Wang, Lei; Yu, Lihong; Xi, Jingyu

    2015-07-01

    A series of highly branched sulfonated poly (fluorenyl ether ketone sulfone)s (HSPAEK) are synthesized by direct polycondensation reactions. The HSPAEK with 8% degree of branching is further investigated as membrane for vanadium redox flow battery (VRFB). The HSPAEK membrane prepared by solution casting method exhibits smooth, dense and tough morphology. It possesses very low VO2+ permeability and high ion selectivity compared to those of Nafion 117 membrane. When applied to VRFB, this novel membrane shows higher coulombic efficiency (CE, 99%) and energy efficiency (EE, 84%) than Nafion 117 membrane (CE, 92% and EE, 78%) at current density of 80 mA cm-2. Besides, the HSPAEK membrane shows super stable CE and EE as well as excellent discharge capacity retention (83%) during 100 cycles life test. After being soaked in 1.5 mol L-1 VO2+ solution for 21 days, the weight loss of HSPAEK membrane and the amount of VO2+ reduced from VO2+ are only 0.26% and 0.7%, respectively, indicating the superior chemical stability of the membrane.

  11. Tin Coatings Electrodeposited from Sulfonic Acid-Based Electrolytes: Tribological Behavior

    NASA Astrophysics Data System (ADS)

    Bengoa, L. N.; Tuckart, W. R.; Zabala, N.; Prieto, G.; Egli, W. A.

    2015-06-01

    A high efficiency methane sulfonic acid electrolyte used for tin electrodeposition was studied, and the properties of the resulting deposits were compared to those of tin coatings obtained from an industrial phenol sulfonic acid electrolyte. Cyclic voltammetry was used to study the effect of organic additives on the reduction process to define the composition of the electrolytic bath. Thick tin electrodeposits were obtained on rotating cylinder steel electrodes, and their surface morphology, preferred crystal orientation, surface roughness, micro hardness, and tribological behavior were measured. Smooth, adherent, and bright tin coatings were obtained from the methane sulfonic acid electrolyte, which differed in morphology and texture from tin electrodeposited from the industrial bath. Influence of organic additives on preferred crystal orientation of the coatings was found to be stronger than changing the supporting sulfonic acid type. Tribological tests showed that the two types of deposits have a similar coefficient of friction. However, tin coatings obtained from methane sulfonic electrolytes presented a lower wear resistance and underwent galling at lower loads.

  12. [Dependence of the anticoagulant activity of starch and inulin on their degree of sulfonation].

    PubMed

    Drozd, N N; Torlopov, M A; Kuzhim, A A; Makarov, V A

    2012-01-01

    We have studied a relationship between the degree of sulfonation and anticoagulant activity of starch from Solanum tuberosum (molecular weight, 25000-30000 Da; sulfonation degree, 0.4-2.5) and inulin from Helianthus tuberosus (molecular weight, 7000-8000 Da; sulfonation degree, 0.6-1.6). Starch and inulin sulfates (i) increased the time of appearance of fibrin clots in plasma in coagulometric tests and (ii) reduced (via antithrombin) the rate of thrombin-induced hydrolysis of a chromogen substrate. The antithrombin (aIIa) activity of starch sulfates reached 16.8-70.0 IU/mg and the activity against factor Xa (aXa activity) was 2.3-16.6 IU/mg. The antithrombin activity of inulin sulfates was within 5.5-11.4 IU/mg and the activity against factor Xa (aXa activity) was within 0-1.4 IU/mg. An increase in the degree of sulfonation led to a growth in the anticoagulant activity of starch sulfates. The anticoagulant activity of starch sulfates and inulin sulfate with sulfonation degree 1.0 is mediated by antithrombin, which is the plasma inhibitor of serine proteases. PMID:22891439

  13. Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Membrane structure and transport properties

    SciTech Connect

    Sodeye, Akinbode; Huang, Tianzi; Gido, Samuel; Mays, Jimmy

    2011-01-01

    With a view to optimizing morphology and ultimately properties, membranes have been cast from relatively inexpensive block copolymer ionomers of fluorinated polyisoprene-block-sulfonated polystyrene (FISS) with various sulfonation levels, in both the acid form and the cesium neutralized form. The morphology of these membranes was characterized by transmission electron microscopy and ultra-small angle X-ray scattering, as well as water uptake, proton conductivity and methanol permeability within the temperature range from 20 to 60 C. Random phase separated morphologies were obtained for all samples except the cesium sample with 50 mol% sulfonation. The transport properties increased with increasing degree of sulfonation and temperature for all samples. The acid form samples absorbed more water than the cesium samples with a maximum swelling of 595% recorded at 60 C for the acid sample having 50 mol% sulfonation. Methanol permeability for the latter sample was more than an order of magnitude less than for Nafion 112 but so was the proton conductivity within the plane of the membrane at 20 C. Across the plane of the membrane this sample had half the conductivity of Nafion 112 at 60 C.

  14. Ionomers based on multisulfonated perylene dianhydride: Synthesis and properties of water resistant sulfonated polyimides

    NASA Astrophysics Data System (ADS)

    Zhang, Feng; Li, Nanwen; Zhang, Suobo; Li, Shenghai

    A novel locally and densely sulfonated dianhydride with four sulfonic acid groups, 1,6,7,12-tetra[4-(sulfonic acid)phenoxy]perylene-3,4,9,10-tetracarboxylic dianhydride (SPTDA), was successfully synthesized by direct sulfonation of the parent dianhydride, 1,6,7,12-tetraphenoxyperylene-3,4,9,10-tetracarboxylic dianhydride (PTDA). Sulfonated copolyimides were prepared from SPTDA, nonsulfonated dianhydride 4,4‧-binaphthyl-1,1‧,8,8‧-tetracarboxylic dianydride, 4,4‧-diaminodiphenyl ether (a) or dodecane-1,12-diamine (b). The synthesized copolymers, with the -SO 3H group on the polymer side chain, possess high molecular weights and high viscosities, and they form tough, flexible membranes. The copolymer membrane with an ion exchange capacity of 2.69 mequiv. g -1 had a proton conductivity of 0.126 S cm -1 at 20 °C and 0.292 S cm -1 at 100 °C; the latter is much higher than that of Nafion ® 117 under the same conditions. The mechanical properties of the copolymer membranes were almost unchanged after accelerated water stability testing at 140 °C for 100 h; this indicates excellent hydrolytic stability of the synthesized copolyimides.

  15. Improving the Serum Stability of Site-Specific Antibody Conjugates with Sulfone Linkers

    PubMed Central

    2015-01-01

    Current routes for synthesizing antibody–drug conjugates commonly rely on maleimide linkers to react with cysteine thiols. However, thioether exchange with metabolites and serum proteins can compromise conjugate stability and diminish in vivo efficacy. We report the application of a phenyloxadiazole sulfone linker for the preparation of trastuzumab conjugates. This sulfone linker site-specifically labeled engineered cysteine residues in THIOMABs and improved antibody conjugate stability in human plasma at sites previously shown to be labile for maleimide conjugates. Similarly, sulfone conjugation with selenocysteine in an anti-ROR1 scFv-Fc improved human plasma stability relative to maleimide conjugation. Kinetically controlled labeling of a THIOMAB containing two cysteine substitutions was also achieved, offering a strategy for producing antibody conjugates with expanded valency. PMID:25099687

  16. Nuclear Magnetic Resonance Identification of New Sulfonic Acid Metabolites of Chloroacetanilide Herbicides

    USGS Publications Warehouse

    Morton, M.D.; Walters, F.H.; Aga, D.S.; Thurman, E.M.; Larive, C.K.

    1997-01-01

    The detection of the sulfonic acid metabolites of the chloroacetanilide herbicides acetochlor, alachlor, butachlor, propachlor, and, more recently, metolachlor in surface and ground water suggests that a common mechanism for dechlorination exists via the glutathione conjugation pathway. The identification of these herbicides and their metabolites is important due to growing public awareness and concern about pesticide levels in drinking water. Although these herbicides are regulated, little is known about the fate of their metabolites in soil. The sulfonic acid metabolites were synthesized by reaction of the parent compounds with an excess of sodium sulfite. Acetochlor, alachlor, butachlor, metolachlor, and propachlor and their sulfonic acid metabolites were studied by nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. This paper provides a direct method for the preparation and characterization of these compounds that will be useful in the analysis and study of chloracetanilide herbicides and their metabolites.

  17. [Sensitivity to sodium dodecyl benzene sulfonate: a supplementary test for bacterial identification].

    PubMed

    Serov, G D

    1981-01-01

    The susceptibility to sodium dodecylbenzene sulfonate, an anion-active detergent, was studied with 10 Gram-positive and 18 Gram-negative bacterial cultures. According to this susceptibility, the cultures were subdivided into two groups identical in their tinctorial properties. The bacteria growing at a 0.05% concentration of sodium dodecylbenzene sulfonate or at its higher concentrations were Gram-negative. The threshold concentration of this compound in the medium at which Gram-positive cultures could grow was 0.008%; some of the bacteria ceased growing even at a 0.002% concentration. The bacteria varied in their susceptibility to the detergent also within one and the same group, and even within one and the same species. The subdivision of bacteria on the basis of their susceptibility to sodium dodecylbenzene sulfonate may be considered as a taxonomic feature. PMID:7321918

  18. Cyclization of gold acetylides: synthesis of vinyl sulfonates via gold vinylidene complexes.

    PubMed

    Bucher, Janina; Wurm, Thomas; Nalivela, Kumara Swamy; Rudolph, Matthias; Rominger, Frank; Hashmi, A Stephen K

    2014-04-01

    Differently substituted terminal alkynes that bear sulfonate leaving groups at an appropriate distance were converted in the presence of a propynyl gold(I) precatalyst. After initial formation of a gold acetylide, a cyclization takes place at the β-carbon atom of this species. Mechanistic studies support a mechanism that is related to that of dual gold-catalyzed reactions, but for the new substrates, only one gold atom is needed for substrate activation. After formation of a gold vinylidene complex, which forms a tight contact ion pair with the sulfonate leaving group, recombination of the two parts delivers vinyl sulfonates, which are valuable targets that can serve as precursors for cross-coupling reactions, for example. PMID:24596326

  19. endo-3,3-Dimethyl-4-oxobicyclo-[3.1.0]hexan-2-yl methane-sulfonate.

    PubMed

    Kremer, Adrian; Norberg, Bernadette; Krief, Alain; Wouters, Johan

    2010-01-01

    The relative configuration of the endo isomer of the title compound, C(9)H(14)O(4)S, has been established and the conformation of the diastereoisomer is discussed. The five-membered ring adopts an envelope conformation. The conformation of the methane-sulfonate substituent is stabilized by inter-molecular C-H⋯O hydrogen bonds. The crystal packing results in alternating layers of polar methane-sulfonates and stacked bicyclo-hexa-nyl rings parallel to ab. PMID:21580752

  20. Segmented tetrasulfonated copoly(arylene ether sulfone)s: improving proton transport properties by extending the ionic sequence.

    PubMed

    Takamuku, Shogo; Weiber, E Annika; Jannasch, Patric

    2013-02-01

    The morphologies and proton-transport efficiencies of segmented copoly(arylene ether sulfone) ionomers that contain tetrasulfonated sequences are compared with the corresponding copolymers with disulfonated sequences. Tetrasulfonated 4,4'-bis[(4-chlorophenyl)sulfonyl]-1,1'-biphenyl (sBCPSBP) is synthesized by metalation and sulfination. This new monomer is then used in K(2)CO(3)-mediated polycondensations of mixtures with 4,4'-dichlorodiphenyl sulfone (DCDPS) and 4,4'-dihydroxybiphenyl in dimethyl sulfoxide at 110 °C to prepare segmented copolymers with tetrasulfonated units. The corresponding disulfonated copolymers are prepared by using disulfonated DCDPS instead of sBCPSBP. Small-angle X-ray scattering measurements of the fully aromatic copolymer membranes show ionomer peaks that indicate significantly larger characteristic separation lengths of the tetrasulfonated copolymers compared to those of the corresponding disulfonated copolymers with similar ionic contents. This implies a much more efficient phase separation of the ionic groups in the segmented tetrasulfonated copolymer membranes, especially at low-to-medium ionic contents. The enhanced phase separation has a pronounced positive effect on water uptake characteristics and proton transport properties. Under a reduced relative humidity (RH), the tetrasulfonated copolymer membranes show a significantly higher conductivity than the disulfonated ones, particularly at low-to-medium ionic contents. At an ion-exchange capacity of 1 meq g(-1), the conductivity of the tetrasulfonated copolymer membrane at 30 % RH is higher than that of the disulfonated membrane at 90 % RH. Because of their relative ease of synthesis, segmented copolymers based on well-designed multisulfonated monomers may provide a viable alternative to the more complex sulfonated block and graft copolymers for use as fuel-cell membranes. PMID:23307760

  1. Proton conducting sol-gel sulfonated membranes produced from 2-allylphenol, 3-glycidoxypropyl trimethoxysilane and tetraethyl orthosilicate

    NASA Astrophysics Data System (ADS)

    Mosa, J.; Durán, A.; Aparicio, M.

    An important research area in proton exchange membrane fuel cells (PEMFC) is devoted to the development of low cost membranes able to work at temperatures higher than 100 °C. In this work, homogeneous, transparent and crack-free hybrid membranes have been synthesized using tetraethyl orthosilicate (TEOS), 3-glycidoxipropyl trimethoxysilane (GPTMS) and 2-allylphenol (AP) as precursors. The synthesis of proton conducting membranes was performed by a post-sulfonation method using trimethylsilyl chlorosulfonate as a mild sulfonating agent. The water retention properties provided by sulfonate and hydroxyl groups and the high porosity leads to relatively high proton conductivity (maximum values around 1.3 × 10 -3 S cm -1 at 140 °C and 100% RH) for membranes treated at 180 °C and sulfonated for 2 h.

  2. The origin of luminescence from di[4-(4-diphenylaminophenyl)phenyl]sulfone (DAPSF), a blue light emitter: an X-ray excited optical luminescence (XEOL) and X-ray absorption near edge structure (XANES) study.

    PubMed

    Zhang, Duo; Zhang, Hui; Zhang, Xiaohong; Sham, Tsun-Kong; Hu, Yongfeng; Sun, Xuhui

    2016-02-24

    The electronic structure and optical properties of di[4-(4-diphenylaminophenyl)phenyl]sulfone (denoted as DAPSF), a highly efficient fluorophor, have been investigated using X-ray excited optical luminescence (XEOL) and X-ray absorption near edge structure (XANES) spectroscopy at excitation energies across the C, N, O K-edges and the sulfur K-edge. The results indicate that the blue luminescence is mainly related to the sulfur functional group. PMID:26866785

  3. Syntheses, characterizations and crystal structures of two new lead(II) amino and carboxylate-sulfonates with a layered and a pillared layered structure

    NASA Astrophysics Data System (ADS)

    Yuan, Yan-Ping; Mao, Jiang-Gao; Song, Jun-Ling

    2004-03-01

    Reactions of lead(II) acetate with m-aminobenzenesulfonic acid (H L1) and 5-sulfoisophthalic acid (H 3L2) afforded two new lead(II) sulfonates, Pb( L1) 21 and Pb 2( L2)( μ3-OH)(H 2O) 2. In compound 1, the lead(II) ion is eight-coordinated by two sulfonate groups bidentately, two sulfonate groups unidentately and two amino groups from six ligands. Each L1 ligand is tetradentate and bridges with three Pb(II) ions. The interconnection of the Pb(II) ions via bridging sulfonate ligands resulted in <100> and <200> layers. In compound 2, one Pb(II) ion is six-coordinated by a carboxylate group bidentately, by two carboxylate groups unidentately, by a sulfonate oxygen atom and by an OH anion, whereas the other one is six-coordinated by a bidentate chelating carboxylate group, two μ3-OH anions, a sulfonate oxygen atom and an aqua ligand. The interconnection of irregular PbO 6 polyhedra via carboxylate-sulfonate ligands resulted in the formation of a pillared layered structure with the 2D layer being formed; the lead(II) ions, hydroxyl groups, carboxylate and sulfonate groups and the benzene ring as the pillar agent.

  4. Desulfonation of amino sulfonic acids of the benzene series in proton-donor media

    SciTech Connect

    Khelevin, R.N.

    1986-11-10

    In this work the desulfonation of amino sulfonic acids was studied by the determination of the kinetics of homogeneous isotopic exchange in radioactive sulfuric acid labeled with the isotope /sup 35/S, either containing HB(HSO/sub 4/)/sub 4/, or not containing it. The radioactive sulfuric acid was taken in an amount of 20 moles per mole of the amino sulfonic acid. Preliminary experiments showed that under these conditions neither the formation of disulfonic acids, nor the accumulation of desulfonated products occurs.

  5. Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae. Tenth quarterly report

    SciTech Connect

    Krawiec, S.

    1992-02-07

    The original conception of the work was that genetic determinants of the sulfoxide/sulfone/sulfonate/sulfate (``4S``) pathway in Pseudomonas spp. would be cloned in vivo and then transferred to Thiobacillus spp. This ambition remains an appealing prospect; however, fulfilling that ambition has been confounded by an instability observed in the DbtS{sup +} phenotype in Pseudomonas spp. But the persisting interest in the phenotype has lead to isolation of fresh strains which have a DbtS{sup +} phenotype. One strain in particular, N1-36, has been the focus of extensive characterizations in long-term cultures. During the present quarter, seven cultures maintained in a ``fermentor`` for a week or longer have been run to determine rate and extent of growth, extent of conversion of dibenzothiophene (DBT) or dibenzosulfone (DBTO{sub 2}) to monohydroxybiphenyl (OH-BP), effect of pH maintained at 6.0, and the effect of adding glucose to cultures in which the amount of glucose had been diminished by bacterial consumption. In addition, a study of the effectiveness of using R68.445 as a vehicle for in vivo cloning of genes was completed this semester, and introduction of DbtS{sup +} determinants into Thiobacillus spp. continues to be an important goal.

  6. Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae. [Pseudomonas, Thiobacillus, Rhodococcus

    SciTech Connect

    Krawiec, S.

    1992-02-07

    The original conception of the work was that genetic determinants of the sulfoxide/sulfone/sulfonate/sulfate ( 4S'') pathway in Pseudomonas spp. would be cloned in vivo and then transferred to Thiobacillus spp. This ambition remains an appealing prospect; however, fulfilling that ambition has been confounded by an instability observed in the DbtS{sup +} phenotype in Pseudomonas spp. But the persisting interest in the phenotype has lead to isolation of fresh strains which have a DbtS{sup +} phenotype. One strain in particular, N1-36, has been the focus of extensive characterizations in long-term cultures. During the present quarter, seven cultures maintained in a fermentor'' for a week or longer have been run to determine rate and extent of growth, extent of conversion of dibenzothiophene (DBT) or dibenzosulfone (DBTO{sub 2}) to monohydroxybiphenyl (OH-BP), effect of pH maintained at 6.0, and the effect of adding glucose to cultures in which the amount of glucose had been diminished by bacterial consumption. In addition, a study of the effectiveness of using R68.445 as a vehicle for in vivo cloning of genes was completed this semester, and introduction of DbtS{sup +} determinants into Thiobacillus spp. continues to be an important goal.

  7. Sulfonimide-containing poly(arylene ether)s and poly(arylene ether sulfone)s, methods for producing the same, and uses thereof

    DOEpatents

    Hofmann, Michael A.

    2006-11-14

    The present invention is directed to sulfonimide-containing polymers, specifically sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, and processes for making the sulfonimide-containing poly(arylene ether)s and sulfonimide-containing poly(arylene ether sulfone)s, for use conductive membranes and fuel cells.

  8. Exisulind: Aptosyn, FGN 1, Prevatac, sulindac sulfone.

    PubMed

    2004-01-01

    Exisulind [Aptosyn trade mark, FGN 1 trade mark, Prevatac trade mark, sulindac sulfone], the sulfone derivative of sulindac, is the lead compound in a series of selective apoptotic antineoplastic drugs (SAANDs) being developed by OSI Pharmaceuticals. The compounds were originally developed by Cell Pathways, which was acquired by, and integrated into, OSI Pharmaceuticals in June 2003. Exisulind inhibits the enzyme cyclic GMP phosphodiesterase (GMP-PDE), overexpressed in precancerous and cancerous colorectal cells, and induces apoptosis in such cells with minimal effects on normal cells. This apoptotic effect is independent of COX I or COX II inhibition, p53, Bcl-2, or cell-cycle arrest. Preclinical evidence suggests that exisulind also inhibits angiogenesis. Cell Pathways has formed sales and distribution agreements with three healthcare-related companies in the US for its future marketing and support campaign for exisulind. Innovex will hire and train sales representatives for Cell Pathways to launch and promote exisulind, Livingston Healthcare Services will be responsible for customer service, order and distribution administration, and Lash Group will be responsible for the development and implementation of reimbursement support services for exisulind. Cell Pathways has issued an exclusive licence for exisulind to Paladin Labs of Montreal, Canada. The agreement allows Paladin exclusive rights to commercialise the drug in Canada. In August 1999 Cell Pathways submitted an NDA application to the US FDA for exisulind (Aptosyn) for the treatment of familial adenomatous polyposis (FAP). However, in September 2000, the FDA announced that it had found deficiencies in the safety and efficacy data of Cell Pathways' NDA, and returned a non-approvable letter to the company. Cell Pathways then initiated another phase III study of the agent in combination with Aventis' docetaxel and comparing combination therapy with docetaxel alone. Exisulind has fast-track designation for FAP

  9. Boiling significantly promotes photodegradation of perfluorooctane sulfonate.

    PubMed

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K S; Yu, Han-Qing

    2015-11-01

    The application of photochemical processes for perfluorooctane sulfonate (PFOS) degradation has been limited by a low treatment efficiency. This study reports a significant acceleration of PFOS photodegradation under boiling condition compared with the non-boiling control. The PFOS decomposition rate increased with the increasing boiling intensity, but declined at a higher hydronium level or under oxygenation. These results suggest that the boiling state of solution resulted in higher effective concentrations of reactants at the gas-liquid interface and enhanced the interfacial mass transfer, thereby accelerating the PFOS decomposition. This study broadens our knowledge of PFOS photodegradation process and may have implications for development of efficient photodegradation technologies. PMID:26117498

  10. Exploring the nature of interactions among thiophene, thiophene sulfone, dibenzothiophene, dibenzothiophene sulfone and a pyridinium-based ionic liquid.

    PubMed

    Gu, Peng; Lü, Renqing; Liu, Dong; Lu, Yukun; Wang, Shutao

    2014-06-14

    In order to gain an understanding of the nature of the interactions among thiophene (TS), thiophene sulfone (TSO2), dibenzothiophene (DBT), dibenzothiophene sulfone (DBTO2) and the ionic liquid N-butylpyridinium hydrogen sulfate ([BPY][HSO4]), a systematic investigation has been carried out using ab initio methods. The most stable structures indicate that both [BPY](+) and [HSO4](-) play crucial roles in the interactions between TS, TSO2, DBT, DBTO2 and [BPY][HSO4]. Analyses of the most stable optimized structures suggest the occurrence of steric effects, π-π stacking effects, hydrogen bonds, and dihydrogen bonds. The π-π stacking effect in [BPY][HSO4]-TSO2/[BPY][HSO4]-DBTO2 is less significant than that in [BPY][HSO4]-TS/[BPY][HSO4]-DBT, as TSO2 and DBTO2 are more nucleophilic than TS and DBT, resulting in stronger interactions between [BPY][HSO4] and TSO2/DBTO2 than between [BPY][HSO4] and TS/DBT. Thermodynamical data also demonstrate that TSO2/DBTO2 are more prone to interact with [BPY][HSO4] compared with TS/DBT. PMID:24741670

  11. Effects of prenatal exposure to perfluorooctane sulfonate on the developing lung in the rat

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS), an environmentally stable industrial and household compound, has been detected in human and wildlife sera. Chronic prenatal exposure to PFOS in rodents leads to mortality in newborns within hours to days after birth. We have demonstrated that tr...

  12. Remarkable structural diversity and single-crystal-to-single-crystal transformations in sulfone functionalized lanthanide MOFs

    SciTech Connect

    Neofotistou, Eleftheria; Malliakas, Christos D.; Trikalitis, Pantelis N.

    2010-04-13

    We report the formation of novel open framework lanthanide (La, Ce, Pr and Dy) MOFs using the ligand 4,4{prime}-bibenzoic acid-2,2{prime}-sulfone. In the case of Ce and Pr, an unprecedented single-crystal-to-single-crystal transformation at room temperature was discovered.

  13. POLYSTYRENE SULFONIC ACID CATALYZED GREENER SYNTHESIS OF HYDRAZONES IN AQUEOUS MEDIUM USING MICROWAVES

    EPA Science Inventory

    An environmentally benign aqueous protocol for the synthesis of cyclic, bi-cyclic, and heterocyclic hydrazones using polystyrene sulfonic acid (PSSA) as a catalyst has been developed; the simple reaction proceeds efficiently in water in the absence of any organic solvent under mi...

  14. Enantioselective and regioselective pyrone Diels-Alder reactions of vinyl sulfones: total synthesis of (+)-cavicularin.

    PubMed

    Zhao, Peng; Beaudry, Christopher M

    2014-09-22

    The total synthesis of (+)-cavicularin is described. The synthesis features an enantio- and regioselective pyrone Diels-Alder reaction of a vinyl sulfone to construct the cyclophane architecture of the natural product. The Diels-Alder substrate was prepared by a regioselective one-pot three-component Suzuki reaction of a non-symmetric dibromoarene. PMID:25082270

  15. Exposure to perfluorooctane sulfonate during pregnancy in rat and mouse. I: maternal and prenatal evaluations

    EPA Science Inventory

    Abstract: The maternal and developmental toxicities of perfluorooctane sulfonate (PFOS, C8F17SO3-) were evaluated in the rat and mouse. PFOS is an environmentally persistent compound used as a surfactant and occurs as a degradation product of both perfluorooctane sulfonyl fluorid...

  16. Synthesis, Characterization, and Catalytic Activity of Sulfonated Carbon-Based Catalysts Derived From Rubber Tree Leaves and Pulp and Paper Mill Waste

    NASA Astrophysics Data System (ADS)

    Janaun, J.; Sinin, E.; Hiew, S. F.; Kong, A. M. T.; Lahin, F. A.

    2016-06-01

    Sulfonated carbon-based catalysts derived from rubber tree leaves, and pulp and paper mill waste were synthesized and characterized. Three types of catalyst synthesized were sulfonated rubber tree leaves (S-RTL), pyrolysed sludge char (P-SC) and sulfonated sludge char (S-SC). Sulfonated rubber tree leaves (S-RTL) and sulfonated sludge char (S-SC) were prepared through pyrolysis followed by functionalization via sulfonation process whereas, P- SC was only pyrolyzed without sulfonation. The characterization results indicated sulfonic acids, hydroxyl, and carboxyl moieties were detected in S-RTL and S-SC, but no sulfonic acid was detected in P-SC. Total acidity test showed S-RTL had the highest value followed by S-SC and P-SC. The thermal stability of S-RTL and S-SC were up to 230oC as the loss was associated with the decomposition of sulfonic acid group, whereas, P-SC showed higher stability than the S-RTL and S-SC. Morphology analysis showed that S-RTL consisted of an amorphous carbon structure, and a crystalline structure for P-SC and S-SC. Furthermore, traces of metal components were also detected on all of the catalysts. The catalyst catalytic activity was tested through esterification of oleic acid with methanol. The results showed that the reaction using S-RTL catalyst produced the highest conversion (99.9%) followed by P-SC (88.4%) and lastly S-SC (82.7%). The synthesized catalysts showed high potential to be used in biodiesel production.

  17. A comprehensive study of sulfonated carbon materials as conductive composites for polymer solar cells.

    PubMed

    Ji, Ting; Tan, Licheng; Hu, Xiaotian; Dai, Yanfeng; Chen, Yiwang

    2015-02-14

    Sulfonated carbon nanotubes (S-CNTs) and sulfonated graphene (S-Gra) with superior dispersibility were successfully prepared to modify poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) for applications in polymer solar cells (PSCs). The synergetic effect between S-CNTs/S-Gra and PEDOT:PSS could remove excess insulating PSS chains leading to an obvious phase separation between the PEDOT and PSS chains, which allows the formation of more conductive PEDOT channels. The PEDOT:PSS (Clevios PH 4083):S-CNTs with well-matched work function, favorable morphology, optimized hydrophobicity and superior hole mobility is demonstrated to be an excellent hole transport layer (HTL) for PSCs. However, the PEDOT:PSS (Clevios PH 4083) modified by sulfonated graphene with stacked and wrinkled lamellae as an HTL renders a rough morphology and has a negative impact on the morphology of the active layer, consequently resulting in a poor device performance. Excitingly, PEDOT:PSS (Clevios PH 1000) modified with S-Gra shows high conductivity, because the sulfonated graphene lamellae contribute to the connection between the insulator and conductive PEDOT islands and improves the charge conduction. The PH1000:S-Gra with multiple layers presents excellent electrical conductive properties and a high transmittance (sheet resistance of ∼45 Ω sq(-1) and transmittance of ∼85.5% at 550 nm), which possess great potential for its application as a transparent conductive and flexible electrode in organic electronics. PMID:25563771

  18. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  19. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  20. Sulfonated Nanoplates in Proton Conducting Membranes for Fuel Cells

    SciTech Connect

    Chen, W.F.; Ni’mah, H.; Yu-Cheng Shen, Y.-C.; Kuo, P.-L.

    2011-09-29

    Surface-functionalized nanoplates are synthesized by anchoring sulfonic acid containing siloxanes on zirconium phosphate, and in turn blended with Nafion to fabricate proton conducting membranes. The effects of these sulfonated nanoplates on proton conduction, hydro-characteristics and fuel cell performance are reported.

  1. Synthesis of basic and overbasic sulfonate detergent additives

    SciTech Connect

    Abou El Naga, H.H.; Abd El-Azim, W.M.; Bendary, S.A.; Awad, N.G.

    1993-12-01

    Heavy alkylbenzene, which accumulates as a by-product from linear alkylbenzene synthesis, is evaluated as a starting material for preparation of basic and over basic sulfonate detergent additives. Chemical structure analysis showed that this by-product contains several components in different proportions. Most of these components, as traced via mass spectrometry, showed the presence of paraffinic side chains within the carbon range C{sub 11}--C{sub 22}. Accordingly, sulfonation conditions for it were adjusted to optimize the reaction yield and sulfonic quality. Neutralization of the sulfonic acid was carried out by adding CaO in the presence of methanol as a promoter. Preparation of over basic sulfonate was run via a carbonation process at 55--60 C. Evaluations of synthesized basic calcium sulfonate in comparison to a commercial additive is supported by its efficiency as a detergent additive. The synthesized product has a higher total base number and Ca content than those for the commercial one. On the other hand, evaluation of the synthesized overbasic calcium sulfonate compared with overbasic commercial additives with medium and high alkalinity indicated that the synthesized product can be classified as overbasic calcium sulfonate with medium alkalinity, good dispersive power, and detergent efficiency.

  2. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  3. 40 CFR 721.1625 - Alkylbenzene sulfonate, amine salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkylbenzene sulfonate, amine salt... Substances § 721.1625 Alkylbenzene sulfonate, amine salt. (a) Chemical substance and significant new uses... salt (PMN P-90-456) is subject to reporting under this section for the significant new use described...

  4. Synthesis of cyclic sulfones by ring-closing metathesis.

    PubMed

    Yao, Qingwei

    2002-02-01

    A general and highly efficient synthesis of cyclic sulfones based on ring-closing metathesis has been developed. The synthetic utility of the resulting cyclic sulfones was demonstrated by their participation in stereoselective Diels-Alder reactions and transformation to cyclic dienes by the Ramberg-Bäcklund reaction. PMID:11820896

  5. Controlling Structure in Sulfonated Block Copolymer Membranes

    NASA Astrophysics Data System (ADS)

    Truong, Phuc; Stein, Gila; Strzalka, Joe

    2015-03-01

    In many ionic block copolymer systems, the strong incompatibility between ionic and non-ionic segments will trap non-equilibrium structures in the film, making it difficult to engineer the optimal domain sizes and transport pathways. The goal of this work is to establish a framework for controlling the solid-state structure of sulfonated pentablock copolymer membranes. They have ABCBA block sequence, where A is poly(t-butyl styrene), B is poly(hydrogenated isoprene), and C is poly(styrene sulfonate). To process into films, the polymer is dissolved in toluene/n-propanol solvent mixtures, where the solvent proportions and the polymer loading were both varied. Solution-state structure was measured with small angle X-ray scattering (SAXS). We detected micelles with radii that depend on the solvent composition and polymer loading. Film structure was measured with grazing-incidence SAXS, which shows (i) domain periodicity is constant throughout film thickness; (ii) domain periodicity depends on solvent composition and polymer loading, and approximately matches the micelle radii in solutions. The solid-state packing is consistent with a hard sphere structure factor. Results suggest that solid-state structure can be tuned by manipulating the solution-state self-assembly.

  6. Triclosan is a potent inhibitor of estradiol and estrone sulfonation in sheep placenta

    PubMed Central

    James, Margaret O.; Li, Wenjun; Summerlot, David P.; Rowland-Faux, Laura; Wood, Charles E.

    2016-01-01

    The personal care product Triclosan, 5-chloro-2(2,4-dichlorophenoxy)-phenol, is widely used in consumer products as an antibacterial agent and is increasingly found in the environment as a contaminant of sewage sludge and wastewater. This compound has been identified in plasma and urine of people in the United States, Sweden and Australia. Triclosan is known to inhibit sulfonation of phenolic xenobiotics and is structurally related to inhibitors of estrogen sulfotransferase, such as polychlorobiphenylols. In pregnancy, the placenta is an important source of estrogen, which is needed for normal fetal development and successful parturition, and estrogen sulfotransferase is thought to play an important role in regulation of estrogen availability. In this study, we examined the effect of Triclosan on sheep placental cytosolic sulfotransferase activity with 17-beta-estradiol and estrone as substrates. For comparison, we studied the effects of 4-hydroxy-3,3′,4′,5-tetrachlorobiphenyl and 2′-hydroxytriclocarban on estradiol sulfonation. The apparent Km for placental cytosolic sulfotransferase activity with estradiol as substrate was 0.27±0.06 nM (mean±S.D., n=3 individuals) and with estrone as substrate was 1.86±0.22 nM. Partial substrate inhibition was observed with estradiol at concentrations higher than 10–20 nM, as is typical of estrogen sulfotransferases (SULT1E1) in other species. Studies of the effect of Triclosan on estrogen sulfotransferase activity were conducted with several concentrations (0.1–6 nM) of estradiol and with 2 nM estrone. Triclosan was a very potent inhibitor of both estradiol and estrone sulfonation. For estradiol the inhibition was shown to be mixed competitive/uncompetitive, with Kic of 0.09±0.01 nM and Kiu of 5.2±2.9 nM. The IC50 for inhibition of estrone sulfonation was 0.60±0.06 nM. At an environmentally relevant concentration of 1 μM, Triclosan was not a substrate for glucuronidation in sheep placental microsomes. Triclosan

  7. Crystal structure of sodium (1S)-d-lyxit-1-yl-sulfonate.

    PubMed

    Haines, Alan H; Hughes, David L

    2016-05-01

    The title compound, Na(+)·C5H11O8S(-) [systematic name: sodium (1S,2S,3S,4R)-1,2,3,4,5-penta-hydroxy-pentane-1-sulfonate], is formed by reaction of d-lyxose with sodium bis-ulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure in which one of the oxygen atoms of the sulfonate residue, the S atom, the C atoms of the sugar chain and the O atom of the hy-droxy-methyl group form an essentially planar zigzag chain with the corresponding torsion angles lying between 179.80 (11) and 167.74 (14)°. A three-dimensional bonding network exists in the crystal structure involving hexa-coordination of sodium ions by O atoms, three of which are provided by a single d-lyxose-sulfonate unit and the other three by two sulfonate groups and one hy-droxy-methyl group, each from separate units of the adduct. Extensive inter-molecular O-H⋯O hydrogen bonding supplements this bonding network. PMID:27308005

  8. Crystal structure of sodium (1S)-d-lyxit-1-yl­sulfonate

    PubMed Central

    Haines, Alan H.; Hughes, David L.

    2016-01-01

    The title compound, Na+·C5H11O8S− [systematic name: sodium (1S,2S,3S,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate], is formed by reaction of d-lyxose with sodium bis­ulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure in which one of the oxygen atoms of the sulfonate residue, the S atom, the C atoms of the sugar chain and the O atom of the hy­droxy­methyl group form an essentially planar zigzag chain with the corresponding torsion angles lying between 179.80 (11) and 167.74 (14)°. A three-dimensional bonding network exists in the crystal structure involving hexa­coordination of sodium ions by O atoms, three of which are provided by a single d-lyxose–sulfonate unit and the other three by two sulfonate groups and one hy­droxy­methyl group, each from separate units of the adduct. Extensive inter­molecular O—H⋯O hydrogen bonding supplements this bonding network. PMID:27308005

  9. Red electroluminescence of ruthenium sensitizer functionalized by sulfonate anchoring groups.

    PubMed

    Shahroosvand, Hashem; Abbasi, Parisa; Mohajerani, Ezeddin; Janghouri, Mohammad

    2014-06-28

    We have synthesized five novel Ru(ii) phenanthroline complexes with an additional aryl sulfonate ligating substituent at the 5-position [Ru(L)(bpy)2](BF4)2 (1), [Ru(L)(bpy)(SCN)2] (2), [Ru(L)3](BF4)2 (3), [Ru(L)2(bpy)](BF4)2 (4) and [Ru(L)(BPhen)(SCN)2] (5) (where L = 6-one-[1,10]phenanthroline-5-ylamino)-3-hydroxynaphthalene 1-sulfonic, bpy = 2,2'-bipyridine, BPhen = 4,7-diphenyl-1,10-phenanthroline), as both photosensitizers for oxide semiconductor solar cells (DSSCs) and light emitting diodes (LEDs). The absorption and emission maxima of these complexes red shifted upon extending the conjugation of the phenanthroline ligand. Ru phenanthroline complexes exhibit broad metal to ligand charge transfer-centered electroluminescence (EL) with a maximum near 580 nm. Our results indicated that a particular structure (2) can be considered as both DSSC and OLED devices. The efficiency of the LED performance can be tuned by using a range of ligands. Device (2) has a luminance of 550 cd m(-2) and maximum efficiency of 0.9 cd A(-1) at 18 V, which are the highest values among the five devices. The turn-on voltage of this device is approximately 5 V. The role of auxiliary ligands in the photophysical properties of Ru complexes was investigated by DFT calculation. We have also studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phenanthroline complexes and an iodine redox electrolyte. A solar energy to electricity conversion efficiency (η) of 0.67% was obtained for Ru complex (2) under standard AM 1.5 irradiation with a short-circuit photocurrent density (Jsc) of 2.46 mA cm(-2), an open-circuit photovoltage (Voc) of 0.6 V, and a fill factor (ff) of 40%, which are all among the highest values for ruthenium sulfonated anchoring groups reported so far. Monochromatic incident photon to current conversion efficiency was 23% at 475 nm. Photovoltaic studies clearly indicated dyes with two SCN substituents yielded a higher Jsc for the

  10. Wine metabolomics reveals new sulfonated products in bottled white wines, promoted by small amounts of oxygen.

    PubMed

    Arapitsas, Panagiotis; Ugliano, Maurizio; Perenzoni, Daniele; Angeli, Andrea; Pangrazzi, Paolo; Mattivi, Fulvio

    2016-01-15

    The impact of minute amounts of oxygen in the headspace on the post-bottling development of wine is generally considered to be very important, since oxygen can either damage or improve the quality of wine. This project aimed to gain new experimental evidence about the chemistry of the interaction between wine and oxygen. The experimental design included 216 bottles of 12 different white wines produced from 6 different cultivars (Inzolia, Muller Thurgau, Chardonnay, Grillo, Traminer and Pinot gris). Half of them were bottled using the standard industrial process with inert headspace and the other half without inert gas and with extra headspace. After 60 days of storage at room temperature, the wines were analysed using an untargeted LC-MS method. The use of a detailed holistic analysis workflow, with several levels of quality control and marker selection, gave 35 metabolites putatively induced by the different amounts of oxygen. These metabolite markers included ascorbic acid, tartaric acid and various sulfonated compounds observed in wine for the first time (e.g. S-sulfonated cysteine, glutathione and pantetheine; and sulfonated indole-3-lactic acid hexoside and tryptophol). The consumption of SO2 mediated by these sulfonation reactions was promoted by the presence of higher levels of oxygen on bottling. PMID:26709023

  11. Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

    NASA Astrophysics Data System (ADS)

    Chang, Binbin; Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng

    2015-01-01

    Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl2 using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl2 at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of -SO3H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N2 adsorption-desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of -SO3H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of -SO3H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and -SO3H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles.

  12. Distinct sulfonation activities in resveratrol-sensitive and resveratrol-insensitive human glioblastoma cells.

    PubMed

    Sun, Zheng; Li, Hong; Shu, Xiao-Hong; Shi, Hui; Chen, Xiao-Yan; Kong, Qing-You; Wu, Mo-Li; Liu, Jia

    2012-07-01

    Glioblastoma multiforme (GBM) cells show different responses to resveratrol, for unknown reasons. Our data from human medulloblastoma cells and primary cultures of rat brain cells revealed an inverse correlation of sulfonation activity with resveratrol sensitivities, providing a clue to the underlying mechanisms of the variable sensitivities of GBM cells to resveratrol. In this study, we found that U251 cells were sensitive and LN229 cells were insensitive to resveratrol. Thus, these two cell lines were taken as comparable models for elucidating the influence of sulfonation activities on resveratrol sensitivity. HPLC showed identical resveratrol metabolic patterns in both cell lines. LC/MS and high-resolution mass MS analyses further demonstrated that resveratrol monosulfate generated by sulfotransferases (SULTs) was the major metabolite of human GBM cells. The levels of brain-associated SULT (SULT1A1, SULT1C2, and SULT4A1) expression in U251 cells were lower than those in LN229 cells, suggesting the inverse relationship of SULT-mediated sulfonation activity with high intracellular resveratrol bioavailability and resveratrol sensitivity of human GBM cells. Furthermore, immunohistochemical staining revealed reductions in expression of the three brain-associated SULTs in 72.8%, 47.5% and 66.3% of astrocytomas, respectively. Therefore, the levels of brain-associated SULTs and sulfonation activity mediated by them could be important parameters for evaluating the potential response of human GBM cells to resveratrol, and may have value in the personalized treatment of GBMs with resveratrol. PMID:22540632

  13. Chitin nanowhisker-supported sulfonated poly(ether sulfone) proton exchange for fuel cell applications.

    PubMed

    Zhang, Chan; Zhuang, Xupin; Li, Xiaojie; Wang, Wei; Cheng, Bowen; Kang, Weimin; Cai, Zhanjun; Li, Mengqin

    2016-04-20

    To balance the relationship among proton conductivity and mechanic strength of sulfonated poly(ether sulfone) (SPES) membrane, chitin nanowhisker-supported nanocomposite membranes were prepared by incorporating whiskers into SPES. The as-prepared chitin whiskers were prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) mediated oxidation of α-chitin from crab shells. The structure and properties of the composite membranes were examined as proton exchange membrane (PEM). Results showed that chitin nanowhiskers were dispersed incompactly in the SPES matrix. Thermal stability, mechanical properties, water uptake and proton conductivity of the nanocomposite films were improved from those of the pure SPES film with increasing whisker content, which ascribed to strong interactions between whiskers and between SPES molecules and chitin whiskers via hydrogen bonding. These indicated that composition of filler and matrix got good properties and whisker-supported membranes are promising materials for PEM. PMID:26876844

  14. Electrical conductivity of sulfonated poly(ether ether ketone) based composite membranes containing sulfonated polyhedral oligosilsesquioxane

    NASA Astrophysics Data System (ADS)

    Celso, Fabricio; Mikhailenko, Serguei D.; Rodrigues, Marco A. S.; Mauler, Raquel S.; Kaliaguine, Serge

    2016-02-01

    Composite proton exchange membranes (PEMs) intended for fuel cell applications were prepared by embedding of various amounts of dispersed tri-sulfonic acid ethyl POSS (S-Et-POSS) and tri-sulfonic acid butyl POSS (S-Bu-POSS) in thin films of sulfonated poly ether-ether ketone. The electrical properties of the PEMs were studied by Impedance spectroscopy and it was found that their conductivity σ changes with the filler content following a curve with a maximum. The water uptake of these PEMs showed the same dependence. The investigation of initial isolated S-POSS substances revealed the properties of typical electrolytes, which however in both cases possessed low conductivities of 1. 17 × 10-5 S cm-1 (S-Et-POSS) and 3.52 × 10-5 S cm-1 (S-Bu-POSS). At the same time, the insoluble in water S-POSS was found forming highly conductive interface layer when wetted with liquid water and hence producing a strong positive impact on the conductivity of the composite PEM. Electrical properties of the composites were analysed within the frameworks of effective medium theory and bounding models, allowing to evaluate analytically the range of possible conductivity values. It was found that these approaches produced quite good approximation of the experimental data and constituted a fair basis for interpretation of the observed relationship.

  15. Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

    SciTech Connect

    Chang, Binbin Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng

    2015-01-15

    Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl{sub 2} using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl{sub 2} at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of –SO{sub 3}H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N{sub 2} adsorption–desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of –SO{sub 3}H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of –SO{sub 3}H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and –SO{sub 3}H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles. - Graphical abstract: Sulfonated porous carbon nanospheres with high surface area and superior catalytic performance were prepared by a facile chemical activation route. - Highlights: • Porous carbon spheres solid acid prepared by a facile chemical activation. • It owns high surface area, superior porosity and uniform spherical morphology. • It possesses

  16. Sulfonated-polyethyleneimine for Photosensitizer Conjugation and Targeting

    PubMed Central

    Chitgupi, Upendra; Zhang, Yumiao; Lo, Chi Y.; Shao, Shuai; Song, Wentao; Geng, Jumin; Neelamegham, Sriram; Lovell, Jonathan F.

    2015-01-01

    Polysulfonated macromolecules are known to bind selectins, adhesion membrane proteins which are broadly implicated in inflammation. Commercially available branched polyethyleneimine (PEI) was reacted with chlorosulfonic acid to generate sulfonated PEI with varying degrees of sulfonation. Remaining unreacted amine groups were then used for straightforward conjugation with pyropheophoribide-a, a near infrared photosensitizer. Photosensitizer-labeled sulfonated PEI conjugates inhibited blood coagulation and were demonstrated to specifically bind to cells genetically programmed to overexpress L-selectin (CD62L) or P-selectin (CD62P). In vitro, following targeting, selectin-expressing cells could be destroyed via photodynamic therapy. PMID:26057017

  17. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  18. Surface adsorption of sulfonated poly(phenylene sulfone)/C14TAB mixtures and its correlation with foam film stability.

    PubMed

    Uhlig, Martin; Miller, Reinhard; Klitzing, Regine von

    2016-07-21

    Polyelectrolyte/surfactant mixtures of rigid monosulfonated poly(phenylene sulfone) (sPSO2-220) and tetradecyl trimethylammonium bromide (C14TAB) were investigated by surface tension, surface elasticity and foam film stability measurements. The results were compared to former measurements of polyelectrolyte/surfactant mixtures containing more flexible polyelectrolytes (PAMPS or PSS and C14TAB). For all polyelectrolyte/surfactant mixtures an increased surface adsorption in comparison to the pure surfactant was detected. Moreover, sPSO2-220/C14TAB mixtures showed a much higher surface activity and foam film stability than mixtures with more flexible polyelectrolytes. The results presented give insight into the surface adsorption and foam film formation of rigid polyelectrolyte/surfactant mixtures. Therefore, this study helps to understand the role of polyelectrolyte backbone rigidity in the formation and stabilization of foam films made from polyelectrolyte/surfactant mixtures. PMID:27338310

  19. Electrochemical Windows of Sulfone-Based Electrolytes for High-Voltage Li-Ion Batteries

    SciTech Connect

    Shao, Nan; Sun, Xiao-Guang; Dai, Sheng; Jiang, Deen

    2011-01-01

    Further development of high-voltage lithium-ion batteries requires electrolytes with electrochemical windows greater than 5 V. Sulfone-based electrolytes are promising for such a purpose. Here we compute the electrochemical windows for experimentally tested sulfone electrolytes by different levels of theory in combination with various solvation models. The MP2 method combined with the polarizable continuum model is shown to be the most accurate method to predict oxidation potentials of sulfone-based electrolytes with mean deviation less than 0.29 V. Mulliken charge analysis shows that the oxidation happens on the sulfone group for ethylmethyl sulfone and tetramethylene sulfone, and on the ether group for ether functionalized sulfones. Large electrochemical windows of sulfone-based electrolytes are mainly contributed by the sulfone group in the molecules which helps lower the HOMO level. This study can help understand the voltage limits imposed by the sulfone-based electrolytes and aid in designing new electrolytes with greater electrochemical windows.

  20. Sulfonic Acid- and Lithium Sulfonate-Grafted Poly(Vinylidene Fluoride) Electrospun Mats As Ionic Liquid Host for Electrochromic Device and Lithium-Ion Battery.

    PubMed

    Zhou, Rui; Liu, Wanshuang; Leong, Yew Wei; Xu, Jianwei; Lu, Xuehong

    2015-08-01

    Electrospun polymer nanofibrous mats loaded with ionic liquids (ILs) are promising nonvolatile electrolytes with high ionic conductivity. The large cations of ILs are, however, difficult to diffuse into solid electrodes, making them unappealing for application in some electrochemical devices. To address this issue, a new strategy is used to introduce proton conduction into an IL-based electrolyte. Poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) copolymer is functionalized with sulfonic acid through covalent attachment of taurine. The sulfonic acid-grafted P(VDF-HFP) electrospun mats consist of interconnected nanofibers, leading to remarkable improvement in dimensional stability of the mats. IL-based polymer electrolytes are prepared by immersing the modified mats in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(+)BF4(-)). It is found that the SO3(-) groups can have Lewis acid-base interactions with the cations (BMIM(+)) of IL to promote the dissociation of ILs, and provide additional proton conduction, resulting in significantly improved ionic conductivity. Using this novel electrolyte, polyaniline-based electrochromic devices show higher transmittance contrast and faster switching behavior. Furthermore, the sulfonic acid-grafted P(VDF-HFP) electrospun mats can also be lithiated, giving additional lithium ion conduction for the IL-based electrolyte, with which Li/LiCoO2 batteries display enhanced C-rate performance. PMID:26167794

  1. Arylsulfatase B Mediates the Sulfonation-Transport Interplay in Human Embryonic Kidney 293 Cells Overexpressing Sulfotransferase 1A3.

    PubMed

    Zhao, Mengjing; Wang, Shuai; Li, Feng; Dong, Dong; Wu, Baojian

    2016-09-01

    Elucidating the intricate relationships between metabolic and transport pathways contributes to improved predictions of in vivo drug disposition and drug-drug interactions. Here we reported that inhibited excretion of conjugative metabolites [i.e., hesperetin 3'-O-sulfate (H3'S) and hesperetin 7-O-sulfate (H7S)] by MK-571 led to reduced metabolism of hesperetin (a maximal 78% reduction) in human embryonic kidney 293 cells overexpressing sulfotransferase 1A3 (named SULT293 cells). The strong dependence of cellular sulfonation on the efflux transport of generated sulfated metabolites revealed an interplay of sulfonation metabolism with efflux transport (or sulfonation-transport interplay). Polymerase chain reaction (PCR) and Western blot analyses demonstrated that SULT293 cells expressed multiple sulfatases such as arylsulfatase A (ARSA), ARSB, and ARSC. Of these three desulfonation enzymes, only ARSB showed significant activities toward hesperetin sulfates. The intrinsic clearance values for the hydrolysis of H3'S and H7S were estimated at 0.6 and 0.5 μl/h/mg, respectively. Furthermore, knockdown of ARSB attenuated the regulatory effect of efflux transporter on cellular sulfonation, whereas overexpression of ABSB enhanced the transporter effect. Taken together, the results indicated that ARSB mediated the sulfonation-transport interplay in SULT293 cells. PMID:27325375

  2. Affinity labelling enzymes with esters of aromatic sulfonic acids

    DOEpatents

    Wong, Show-Chu; Shaw, Elliott

    1977-01-01

    Novel esters of aromatic sulfonic acids are disclosed. The specific esters are nitrophenyl p- and m-amidinophenylmethanesulfonate. Also disclosed is a method for specific inactivation of the enzyme, thrombin, employing nitrophenyl p-amidinophenylmethanesulfonate.

  3. Deciphering Structural Intermediates and Genotoxic Fibrillar Aggregates of Albumins: A Molecular Mechanism Underlying for Degenerative Diseases

    PubMed Central

    Naeem, Aabgeena; Amani, Samreen

    2013-01-01

    The misfolding and aggregation of proteins is involved in some of the most prevalent neurodegenerative disorders. The importance of human serum albumin (HSA) stems from the fact that it is involved in bio-regulatory and transport phenomena. Here the effect of acetonitrile (ACN) on the conformational stability of HSA and by comparison, ovalbumin (OVA) has been evaluated in the presence and absence of NaCl. The results show the presence of significant amount of secondary structure in HSA at 70% ACN and in OVA at 50% ACN, as evident from far-UV Circular Dichroism (CD) and Attenuated Total Reflection Fourier transformed infra red spectroscopy (ATR-FTIR). Tryptophan and 8-Anilino-1-Naphthalene-Sulphonic acid (ANS) fluorescence indicate altered tryptophan environment and high ANS binding suggesting a compact “molten globule”-like conformation with enhanced exposure of hydrophobic surface area. However, in presence of NaCl no intermediate state was observed. Detection of aggregates in HSA and OVA was possible at 90% ACN. Aggregates possess extensive β-sheet structure as revealed by far-UV CD and ATR-FTIR. These aggregates exhibit increase Thioflavin T (Th T) fluorescence with a red shift of Congo red (CR) absorption spectrum. X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) analysis confirmed the presence of fibrillar aggregates. Single cell gel electrophoresis (SCGE) assay of these fibrillar aggregates showed the DNA damage resulting in cell necrosis confirming their genotoxic nature. Some proteins not related to any human disease form fibrils in vitro. In the present study ACN gives access to a model system to study the process of aggregation. PMID:23342075

  4. Binding of polarity-sensitive hydrophobic ligands to erythroid and nonerythroid spectrin: fluorescence and molecular modeling studies.

    PubMed

    Patra, Malay; Mitra, Madhurima; Chakrabarti, Abhijit; Mukhopadhyay, Chaitali

    2014-01-01

    We have used three polarity-sensitive fluorescence probes, 6-propionyl 2-(N,N-dimethyl-amino) naphthalene (Prodan), pyrene and 8-anilino 1-naphthalene sulphonic acid, to study their binding with erythroid and nonerythroid spectrin, using fluorescence spectroscopy. We have found that both bind to prodan and pyrene with high affinities with apparent dissociation constants (Kd) of .50 and .17 μM, for prodan, and .04 and .02 μM, for pyrene, respectively. The most striking aspect of these bindings have been that the binding stoichiometry have been equal to 1 in erythroid spectrin, both in dimeric and tetrameric form, and in tetrameric nonerythroid spectrin. From an estimate of apparent dielectric constants, the polarity of the binding site in both erythroid and nonerythroid forms have been found to be extremely hydrophobic. Thermodynamic parameters associated with such binding revealed that the binding is favored by positive change in entropy. Molecular docking studies alone indicate that both prodan and pyrene bind to the four major structural domains, following the order in the strength of binding to the Ankyrin binding domain > SH3 domain > Self-association domain > N-terminal domain of α-spectrin of both forms of spectrin. The binding experiments, particularly with the tetrameric nonerythroid spectrin, however, indicate more toward the self association domain in offering the unique binding site, since the binding stoichiometry have been 1 in all forms of dimeric and tetrameric spectrin, so far studied by us. Further studies are needed to characterize the hydrophobic binding sites in both forms of spectrin. PMID:24404769

  5. Triple Activity of Lamivudine Releasing Sulfonated Polymers against HIV-1.

    PubMed

    Danial, Maarten; Andersen, Anna H F; Zuwala, Kaja; Cosson, Steffen; Riber, Camilla Frich; Smith, Anton A A; Tolstrup, Martin; Moad, Graeme; Zelikin, Alexander N; Postma, Almar

    2016-07-01

    In this article a library of polymeric therapeutic agents against the human immunodeficiency virus (HIV) is presented. The library of statistical copolymers of varied molar mass was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The synthesized polymers comprise pendent hydroxyl and sulfonated side chains as well as the reverse transcriptase prodrug lamivudine (3TC) attached via a disulfide self-immolative linker. The glutathione mediated release of 3TC is demonstrated as well as the antiviral efficacy against HIV entry and polymerase activity. Although a high degree of polymer sulfonation is required for effective HIV entry inhibition, polymers with approximately ∼50% sulfonated monomer demonstrated potent kinase independent reverse transcriptase inhibition. In addition, the sulfonated polymers demonstrate activity against DNA-DNA polymerase, which suggests that these polymers may exhibit activity against a broad spectrum of viruses. In summary, the polymers described provide a triple-active arsenal against HIV with extracellular activity via entry inhibition and intracellular activity by kinase-dependent lamivudine-based and kinase-independent sulfonated polymer based inhibition. Since these sulfonated copolymers are easily formulated into gels, we envision them to be particularly suited for topical application to prevent the mucosal transmission of viruses, particularly HIV. PMID:27244595

  6. Characterization of a Sulfonated Polycarbonate Resistive Humidity Sensor

    PubMed Central

    Rubinger, Carla P.L.; Calado, Hallen D.R.; Rubinger, Rero M.; Oliveira, Henrique; Donnici, Claudio L.

    2013-01-01

    In this work; resistive moisture sensors were obtained by dip coating sulfonated polycarbonate (SPC) onto silver interdigitated electrodes. Commercial polycarbonate was sulfonated with acetyl sulphate at two different sulfonation degrees corresponding to 9.0 and 18.0 mole %. Impedance spectroscopy was used to investigate the humidity sensing properties at controlled relative humidity (RH%) environments generated from standard saline solutions in the range of 11–90 RH%. For the highest sulfonated sample; in the RH% range investigated (11 to 90%); the sensor impedance changed from 4.7 MΩ to 18 kΩ. Humidity sensors made from sulfonated polycarbonate showed exponential decay behavior of the impedance at constant frequency with the environmental relative humidity. Sample 9SPC presented dielectric relaxation response for environmental humidity between 58 and 90 RH% while sample 18SPC presented dielectric relaxation response for the entire measured range between 11 and 90 RH%. Sulfonated polycarbonate could be a promising material for the fabrication of simple and cheap humidity-sensing sensors for the assessment of relative humidity of the surrounding environment, as suggested by experimental results. PMID:23385415

  7. Modular synthesis of triarylmethanes through palladium-catalyzed sequential arylation of methyl phenyl sulfone.

    PubMed

    Nambo, Masakazu; Crudden, Cathleen M

    2014-01-13

    Triarylmethanes, which are valuable structures in materials, sensing and pharmaceuticals, have been synthesized starting from methyl phenyl sulfone as an inexpensive and readily available template. The three aryl groups were installed through two sequential palladium-catalyzed C-H arylation reactions, followed by an arylative desulfonation. This method provides a new synthetic approach to multisubstituted triarylmethanes using readily available haloarenes and aryl boronic acids, and is also valuable for the preparation of unexplored triarylmethane-based materials and pharmaceuticals. PMID:24307286

  8. Potent glucosidase inhibitors: de-O-sulfonated ponkoranol and its stereoisomer.

    PubMed

    Eskandari, Razieh; Kuntz, Douglas A; Rose, David R; Pinto, B Mario

    2010-04-01

    Ponkoranol, a glucosidase inhibitor isolated from the plant Salacia reticulata, comprises a sulfonium ion with an internal sulfate counterion. An efficient synthetic route to de-O-sulfonated ponkoranol and its 5'-stereoisomer is reported, and it is shown that these compounds are potent glucosidase inhibitors that inhibit a key intestinal human glucosidase, the N-terminal catalytic domain of maltase glucoamylase, with K(i) values of 43 +/- 3 and 15 +/- 1 nM, respectively. PMID:20218632

  9. Proton conducting, composite sulfonated polymer membrane for medium temperature and low relative humidity fuel cells

    NASA Astrophysics Data System (ADS)

    Shin, Dong Won; Kang, Na Rae; Lee, Kang Hyuck; Cho, Doo Hee; Kim, Ji Hoon; Lee, Won Hyo; Lee, Young Moo

    2014-09-01

    Inorganic-organic composite membranes are fabricated using zirconium acetylacetonate nanoparticles and biphenol-based sulfonated poly(arylene ether sulfone) as an inorganic, proton conducting nanomaterial and a polymer matrix, respectively. An amphiphilic surfactant (Pluronic®) induces distribution of the inorganic nanoparticles over the entire polymer membrane. The composite membranes are thermally stable up to 200 °C. Zirconium acetylacetonate improves inter-chain interactions and the robustness of polymer membranes resulting in excellent membrane mechanical properties. In addition, composite membranes show outstanding proton conductivity compared to that of the pristine membrane at medium temperatures (80-120 °C) and low relative humidity (<50%) conditions. This improvement is due to the presence of acetylacetonate anions, which bind water molecules and act as an additional proton conducting site and/or medium. Therefore, the composite membranes significantly outperform the pristine membrane in fuel cell performance tests at medium temperatures and low relative humidity.

  10. Neuroendocrine effects of perfluorooctane sulfonate in rats.

    PubMed Central

    Austin, Maureen E; Kasturi, Badrinarayanan S; Barber, Matthew; Kannan, Kurunthachalam; MohanKumar, Puliyur S; MohanKumar, Sheba M J

    2003-01-01

    Perfluorooctane sulfonate (PFOS) is a degradation product of sulfonyl-based fluorochemicals that are used extensively in industrial and household applications. Humans and wildlife are exposed to this class of compounds from several sources. Toxicity tests in rodents have raised concerns about potential developmental, reproductive, and systemic effects of PFOS. However, the effect of PFOS on the neuroendocrine system has not been investigated thus far. In this study, adult female rats were injected intraperitoneally with 0, 1, or 10 mg PFOS/kg body weight (BW) for 2 weeks. Food and water intake, BW, and estrous cycles were monitored daily. At the end of treatment, PFOS levels in tissues were measured by high-performance liquid chromatography (HPLC) interfaced with electrospray mass spectrometry. Changes in brain monoamines were measured by HPLC with electrochemical detection, and serum corticosterone and leptin were monitored using radioimmunoassay. Treatment with PFOS produced a dose-dependent accumulation of this chemical in various body tissues, including the brain. PFOS exposure decreased food intake and BW in a dose-dependent manner. Treatment with PFOS affected estrous cyclicity and increased serum corticosterone levels while decreasing serum leptin concentrations. PFOS treatment also increased norepinephrine concentrations in the paraventricular nucleus of the hypothalamus. These results indicate that exposure to PFOS can affect the neuroendocrine system in rats. PMID:12948888

  11. Neuroendocrine effects of perfluorooctane sulfonate in rats.

    PubMed

    Austin, Maureen E; Kasturi, Badrinarayanan S; Barber, Matthew; Kannan, Kurunthachalam; MohanKumar, Puliyur S; MohanKumar, Sheba M J

    2003-09-01

    Perfluorooctane sulfonate (PFOS) is a degradation product of sulfonyl-based fluorochemicals that are used extensively in industrial and household applications. Humans and wildlife are exposed to this class of compounds from several sources. Toxicity tests in rodents have raised concerns about potential developmental, reproductive, and systemic effects of PFOS. However, the effect of PFOS on the neuroendocrine system has not been investigated thus far. In this study, adult female rats were injected intraperitoneally with 0, 1, or 10 mg PFOS/kg body weight (BW) for 2 weeks. Food and water intake, BW, and estrous cycles were monitored daily. At the end of treatment, PFOS levels in tissues were measured by high-performance liquid chromatography (HPLC) interfaced with electrospray mass spectrometry. Changes in brain monoamines were measured by HPLC with electrochemical detection, and serum corticosterone and leptin were monitored using radioimmunoassay. Treatment with PFOS produced a dose-dependent accumulation of this chemical in various body tissues, including the brain. PFOS exposure decreased food intake and BW in a dose-dependent manner. Treatment with PFOS affected estrous cyclicity and increased serum corticosterone levels while decreasing serum leptin concentrations. PFOS treatment also increased norepinephrine concentrations in the paraventricular nucleus of the hypothalamus. These results indicate that exposure to PFOS can affect the neuroendocrine system in rats. PMID:12948888

  12. Intercalation of Varied Sulfonates into a Layered MOC: Confinement-Caused Tunable Luminescence and Novel Properties.

    PubMed

    Wen, Yuehong; Sheng, Tianlu; Zhu, Xiaoquan; Zhang, Hao; Zhuo, Chao; Hu, Shengmin; Cao, Wenhai; Wu, Xintao

    2016-04-01

    The pores/channels of porous 3D metal-organic frameworks (MOFs) have been widely applied to incorporate gas, solvent, or organic molecules. On the contrary, the utilization of the interlamellar void of layered metal-organic complexes (MOCs) remains underappreciated, although it is more flexible and available to accommodate molecules with different sizes. In this work, diverse sulfonates have been intercalated purposely into an identical layered MOC, which constructed various novel intercalation compounds possessing fluorescent, white-light emitting, photochromic, homochiral, or nonlinear optical (NLO) properties. With the help of single-crystal X-ray diffraction, their structures and the mutual interactions between the MOC host and the sulfonate guests were characterized. The properties of the guest molecules were tuned and meanwhile some new performances were generated after confining them into the interlayer region. Such a hybrid approach provides an efficient strategy to design and prepare multifunctional materials. PMID:26919304

  13. Stereoconvergent Arylations and Alkenylations of Unactivated Alkyl Electrophiles: Catalytic Enantioselective Synthesis of Secondary Sulfonamides and Sulfones

    PubMed Central

    2015-01-01

    The development of efficient methods for the generation of enantioenriched sulfonamides and sulfones is an important objective for fields such as organic synthesis and medicinal chemistry; however, there have been relatively few reports of direct catalytic asymmetric approaches to controlling the stereochemistry of the sulfur-bearing carbon of such targets. In this report, we describe nickel-catalyzed stereoconvergent Negishi arylations and alkenylations of racemic α-bromosulfonamides and -sulfones that furnish the desired cross-coupling product in very good ee and yield for an array of reaction partners. Mechanistic studies are consistent with the generation of a radical intermediate that has a sufficient lifetime to diffuse out of the solvent cage and to cyclize onto a pendant olefin. PMID:25127186

  14. endo-3,3-Dimethyl-4-oxobicyclo­[3.1.0]hexan-2-yl methane­sulfonate

    PubMed Central

    Kremer, Adrian; Norberg, Bernadette; Krief, Alain; Wouters, Johan

    2010-01-01

    The relative configuration of the endo isomer of the title compound, C9H14O4S, has been established and the conformation of the diastereoisomer is discussed. The five-membered ring adopts an envelope conformation. The conformation of the methane­sulfonate substituent is stabilized by inter­molecular C—H⋯O hydrogen bonds. The crystal packing results in alternating layers of polar methane­sulfonates and stacked bicyclo­hexa­nyl rings parallel to ab. PMID:21580752

  15. Acute toxicity to goldfish of mixtures of chloramines, copper, and linear alkylate sulfonate

    SciTech Connect

    Tsai, C.F.; McKee, J.A.

    1980-01-01

    The toxicity to goldfish (Carassius auratus) of mixtures of chloramines, copper, and linear alkylate sulfonate (LAS) was studied by continuous-flow toxicity tests during an exposure period of 96 hours. The individual toxicities of these three chemicals are either additive or synergistic in mixtures, depending on the rate of toxic action of the individual chemical, the toxicity ratio of the chemicals in the mixtures, and the concentration of the mixtures.

  16. Poly(arylene ether sulfone)s ionomers containing quaternized triptycene groups for alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Zhao, Zhuo; Gong, Feixiang; Zhang, Suobo; Li, Shenghai

    2012-11-01

    A series of poly(arylene ether sulfone)s containing quaternized triptycene groups are synthesized through a chloromethylation reaction following a quaternization process. The resulting ionomers are soluble in polar aprotic solvents; thus, flexible, tough membranes could be prepared by solution casting. Novel anion exchange membranes based on these ionomers are obtained by anion exchange with hydroxide ions. All anion exchange membranes show conductivities above 10-2 S cm-1 at room temperature. The highest hydroxide conductivity is 7.2 × 10-2 S cm-1, which is achieved by the anion exchange membrane with ion exchange capacity (IEC) = 2.61 mmol g-1. Meanwhile, these anion exchange membranes have low water uptake and good dimensional stability even at high IEC values. For example, the membrane water uptake (IEC = 1.97 mmol g-1) is only 21% at room temperature, and the swelling ratio is 11%. The anion exchange membranes are stable in alkaline conditions. All the membranes have no significant change in 4 M NaOH solution at 25 °C after 30 days. All results suggest that these anion exchange membranes have potential application in alkaline fuel cells.

  17. Proton Conductivity of Nafion/Ex-Situ Sulfonic Acid-Modified Stöber Silica Nanocomposite Membranes As a Function of Temperature, Silica Particles Size and Surface Modification

    PubMed Central

    Muriithi, Beatrice; Loy, Douglas A.

    2016-01-01

    The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this may not always be the case. Proton conductivity enhancement of Nafion nanocomposite membranes is very dependent on silica particle size, sometimes depending on experimental conditions, and by surface modification. In this study, Sulfonated Preconcentrated Nafion Stober Silica composites (SPNSS) were prepared by modification of Stober silica particles with mercaptopropyltriethoxysilane, dispersing the particles into a preconcentrated solution of Nafion, then casting the membranes. The mercapto groups were oxidized to sulfonic acids by heating the membranes in 10 wt % hydrogen peroxide for 1 h. At 80 °C and 100% relative humidity, a 20%–30% enhancement of proton conductivity was only observed when sulfonic acid modified particle less than 50 nm in diameter were used. At 120 °C, and 100% humidity, proton conductivity increased by 22%–42% with sulfonated particles with small particles showing the greatest enhancement. At 120 °C and 50% humidity, the sulfonated particles are less efficient at keeping the membranes hydrated, and the composites underperform Nafion and silica-Nafion nanocomposite membranes. PMID:26828525

  18. Proton Conductivity of Nafion/Ex-Situ Sulfonic Acid-Modified Stöber Silica Nanocomposite Membranes As a Function of Temperature, Silica Particles Size and Surface Modification.

    PubMed

    Muriithi, Beatrice; Loy, Douglas A

    2016-01-01

    The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this may not always be the case. Proton conductivity enhancement of Nafion nanocomposite membranes is very dependent on silica particle size, sometimes depending on experimental conditions, and by surface modification. In this study, Sulfonated Preconcentrated Nafion Stober Silica composites (SPNSS) were prepared by modification of Stober silica particles with mercaptopropyltriethoxysilane, dispersing the particles into a preconcentrated solution of Nafion, then casting the membranes. The mercapto groups were oxidized to sulfonic acids by heating the membranes in 10 wt % hydrogen peroxide for 1 h. At 80 °C and 100% relative humidity, a 20%-30% enhancement of proton conductivity was only observed when sulfonic acid modified particle less than 50 nm in diameter were used. At 120 °C, and 100% humidity, proton conductivity increased by 22%-42% with sulfonated particles with small particles showing the greatest enhancement. At 120 °C and 50% humidity, the sulfonated particles are less efficient at keeping the membranes hydrated, and the composites underperform Nafion and silica-Nafion nanocomposite membranes. PMID:26828525

  19. Mechanically and structurally robust sulfonated block copolymer membranes for water purification applications

    NASA Astrophysics Data System (ADS)

    Yeo, J.; Kim, S. Y.; Kim, S.; Ryu, D. Y.; Kim, T.-H.; Park, M. J.

    2012-06-01

    The effective removal of ionic pollutants from contaminated water using negatively charged nanofiltration membranes is demonstrated. Block copolymers comprising polystyrene (PS) and partially hydrogenated polyisoprene (hPI) were synthesized by varying chain architectures. A one step procedure of cross-linking (hPI blocks) and sulfonation reactions (PS chains) was then carried out, which was revealed as an effective method to enhance mechanical integrity of membranes while hydrophilic sulfonated chains remain intact. In particular, the control of chain architecture allows us to create a synergetic effect on optimizing charge densities of the membrane, water permeability, and mechanical integrity under water purification conditions. The best performing membrane can almost completely (>99%) reject various divalent cations and also show NO3- rejection > 85% and Na+ rejection > 87%. Well defined nanostructures (tens of nanometers) as well as the periodically arranged water domains (a few nanometers) within hydrophilic phases of the hydrated membranes were confirmed by in situ neutron scattering experiments.

  20. Interfacial assignment of branched-alkyl benzene sulfonates: A molecular simulation

    NASA Astrophysics Data System (ADS)

    Liu, Zi-Yu; Wei, Ning; Wang, Ce; Zhou, He; Zhang, Lei; Liao, Qi; Zhang, Lu

    2015-11-01

    A molecular dynamics simulation was conducted to analyze orientations of sodium branched-alkyl benzene sulfonates molecules at nonane/water interface, which is helpful to design optimal surfactant structures to achieve ultralow interfacial tension (IFT). Through the two dimensional density profiles, monolayer collapses are found when surfactant concentration continues to increase. Thus the precise scope of monolayer is certain and orientation can be analyzed. Based on the simulated results, we verdict the interfacial assignment of branched-alkyl benzene sulfonates at the oil-water interface, and discuss the effect of hydrophobic tail structure on surfactant assignment. Bigger hydrophobic size can slow the change rate of surfactant occupied area as steric hindrance, and surfactant meta hydrophobic tails have a stronger tendency to stretch to the oil phase below the collapsed concentration. Furthermore, an interfacial model with reference to collapse, increasing steric hindrance and charge repulsive force between interfacial surfactant molecules, responsible for effecting of surfactant concentration and structure has been supposed.

  1. Electrocoagulation of commercial naphthalene sulfonates: process optimization and assessment of implementation potential.

    PubMed

    Olmez-Hanci, Tugba; Kartal, Zeynep; Arslan-Alaton, Idil

    2012-05-30

    The commercially important naphthalene sulfonate K-acid (C(10)H(9)NO(9)S(3); 2-naphthylamine 3,6,8-tri sulfonic acid) was subjected to electrocoagulation employing stainless steel electrodes. An experimental design tool was used to mathematically describe and optimize the single and combined influences of major process variables on K-acid and its organic carbon (COD and TOC) removal efficiencies as well as electrical energy consumption. Current density, followed by treatment time were found to be the parameters affecting process responses most significantly, whereas initial K-acid concentration had the least influence on the electrocoagulation performance. Process economics including sludge generation, electrode consumption, and electrochemical efficiency, as well as organically bound adsorbable halogen formation and toxicity evolution were primarily considered to question the feasibility of K-acid electrocoagulation. Considering process economics and ecotoxicological parameters, process implementation appeared to be encouraging. PMID:22318240

  2. Development of sulfonated FEP Nafion hybrid proton exchange membranes for PEFC

    NASA Astrophysics Data System (ADS)

    Sato, Y.; Fujii, K.; Mitani, N.; Matsuura, A.; Kakigi, T.; Muto, F.; Li, J.; Oshima, A.; Washio, M.

    2007-12-01

    The performance of polymer electrolyte fuel cell (PEFC) is affected by an interfacial property between a proton exchange membrane (PEM) and electrodes. Thus, to develop a well-laminated membrane electrode assembly (MEA), a hybrid PEM (FN) was fabricated by mixing a radiation grafted membrane (sulfonated FEP) with ionomer (Nafion ® dispersion) which is applied to coat the interface of the PEM and electrodes. The obtained FN, sulfonated FEP and Nafion ®112 were characterized in terms of water uptake, ion exchange capacity (IEC), polarization performance and electrochemical impedance. FN showed high IEC and water uptake, which would induce the highest ionic conductivity (IC) among tested PEMs. In terms of FN, the interface between the PEM and electrodes should have been improved because FN showed the lowest charge transfer resistance than other tested PEMs. The high IC and improved interface between the PEM and electrodes resulted in the best cell performance of FN in tested PEMs.

  3. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    SciTech Connect

    Kim, Yu Seung; Liu, Baijun; Hu, Wei; Jiang, Zhenhua; Robertson, Gilles; Guiver, Michael

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  4. Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

    NASA Astrophysics Data System (ADS)

    Kordoghli, Bessem; Khiari, Ramzi; Mhenni, Mohamed Farouk; Sakli, Faouzi; Belgacem, Mohamed Naceur

    2012-10-01

    This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of sbnd SO3H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

  5. Sulfonated Poly(Ether-Ether-Ketone) Polymer Membranes for Fuel Cells

    NASA Astrophysics Data System (ADS)

    Hodakovska, J.; Kleperis, J.

    2008-01-01

    In the work, sulfonated poly(ether-ether-ketone) (SPEEK) ionomers were synthesized using an original (submitted for patent) and simple method. The resulting membranes were tested to determine parameters that are important for the use of this material in fuel cells (water absorption, sulfonation degree, conductivity, etc.). The thermo-gravimetric analysis has shown a good thermal stability in the range from RT to 200-220 °C, and two characteristic regions of weight loss - 7.4% at ~140 °C (reversible water loss) and 10.3% at 200-220 °C (due to polymer degradation when cross-linked polymer chains permanently break down and their SO3H-groups are lost). The conductivity values obtained by the through-plane measurements of SPEEK membranes were 12 mS/cm at RT and 23 mS/cm at 80 °C.

  6. Sulfonate groups grafted on Ti6Al4V favor MC3T3-E1 cell performance in serum free medium conditions.

    PubMed

    Felgueiras, Helena; Migonney, Véronique

    2014-06-01

    Ten years ago, we synthesized "bioactive model polymers" bearing sulfonate groups and proposed a mechanism of their modulation effect at different steps of the cell response. Then, we set up the grafting of polymers bearing sulfonate on Ti6Al4V surfaces by a grafting "from" technique making sure of the creation of covalent bonds between the grafted polymer and the Ti6Al4V surface. We have checked and confirmed the positive effect of grafted sulfonate groups on the osteoblastic cell response in vivo and in vitro but we did not elucidate the mechanism. The aim of this basic work consists first in investigating the role of sulfonate groups in the presence and in the absence of proteins at early stages of the osteointegration process on poly(sodium styrene sulfonate) poly(NaSS) grafted and ungrafted Ti6Al4V surfaces, in vitro. To understand the role of poly(NaSS) grafted chains on osteoblast-like cell response and to confirm/elucidate the importance of fetal bovine serum (FBS) proteins in the culture medium, MC3T3-E1 cells were seeded onto poly(NaSS) grafted and non-grafted Ti6Al4V surfaces. Cultures were carried out in a complete (10% FBS) and in a non-complete medium (without FBS). Cell viability assay, cell attachment number and cell adhesion strength were followed up to 3days of culture. The presence of proteins enhanced cell growth and development whatever the surface and the presence of sulfonate groups enhanced the cell attachment even in the absence of proteins, which suggests and confirms that the sulfonate groups can modify the activity of cells such as the secretion of binding proteins. Statistical differences were found in the attachment strength tests on poly(NaSS) grafted and ungrafted surfaces and showed that the sulfonate groups play an important role in the cell resistance to shear stress. PMID:24863216

  7. Visible-light induced oxidant-free oxidative cross-coupling for constructing allylic sulfones from olefins and sulfinic acids.

    PubMed

    Zhang, Guoting; Zhang, Lingling; Yi, Hong; Luo, Yi; Qi, Xiaotian; Tung, Chen-Ho; Wu, Li-Zhu; Lei, Aiwen

    2016-08-16

    An oxidant-free dehydrogenative sulfonylation of α-methyl-styrene derivatives was developed for the construction of allylic sulfones by using eosin Y as a photosensitizer in conjunction with a cobaloxime catalyst. The process features a low-cost metal catalyst and atom economy, which provides an appealing strategy for future synthetic chemistry. PMID:27481529

  8. High lipophilicity of perfluoroalkyl carboxylate and sulfonate: implications for their membrane permeability.

    PubMed

    Jing, Ping; Rodgers, Patrick J; Amemiya, Shigeru

    2009-02-18

    Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of a homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, approximately 2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

  9. New cation-exchange material based on a sulfonated 3,4-ethylenedioxythiophene monomer

    NASA Astrophysics Data System (ADS)

    Stéphan, O.; Schottland, P.; Le Gall, P.-Y.; Chevrot, C.

    1998-06-01

    The electrochemical oxidation, in aqueous medium, of a 3,4-ethylenedioxythiophene monomer functionalized by a sulfonate group exhibiting cation-exchange properties, allows the synthesis of a new type of water-soluble material. In order to synthesize in water, by oxidative electropolymerization, polymer films of controlled thickness containing attached sulfonate groups, we have investigated the polymerization of the functionalized monomer in the presence of the unsubstituted one without supporting electrolyte. Using an equimolar mixture (0.01 mol/l) of both monomers, copolymers exhibiting cation exchange abilities have been synthesized. As an example, th easy incorporation of hexaamine-ruthenium(III) into one of these copolymers is briefly reported. L'oxydation électrochimique en milieu aqueux d'un monomère de type 3,4- éthylènedioxythiophène fonctionnalisé par un groupement sulfonate permet d'envisager la synthèse d'un nouveau type de polymère hydrosoluble. Afin d'obtenir électrochimiquement en milieu aqueux, un film de polymère d'épaisseur contrôlée contenant des groupements sulfonates, nous avons evisagé de polymériser ce monomère en présence de son homologue non substitué. En partant d'un mélange équimolaire (0.01 mol/l) des deux monomères et en l'absence d'électrolyte support, nous avons synthétisé un matériau possédant des propriétés d'échange de cations. A titre d'exemple, nous présentons brièvement l'incorporation d'un complexe hexaaminé du ruthénium(III) dans un de ces copolymères.

  10. Genotoxicity of chryseno[4,5-bcd]thiophene and its sulfone derivative

    SciTech Connect

    Sinsheimer, J.E.; Hooberman, B.H.; Das, S.K.; Savla, P.M.; Ashe, A.J. III )

    1992-01-01

    The authors' recent syntheses of cryseno[4,5-bcd]thiophene together with its potential sulfone metabolite, chryseno[4,5-bcd]thiophene-4,4-dioxide, have made these compounds available for genotoxicity testing. Such toxicity testing is of interest as this thiophene is an isoster of the established carcinogen benzo[a]pyrene and is one of the thiaarenes which are potential environmental contaminants found in fossil fuels. Although the thiophene was less mutagenic than benzo[a]pyrene in Salmonella strains TA98 and TA100 after S9 activation, it exhibited in vivo chromosomal aberration activity equal to that of benzo[a]pyrene in the bone-marrow cells of mice. A reduced activity with Salmonella as well as in the bone-marrow cell assay for the sulfone does not support its role as the key active metabolic intermediate for the genotoxicity of the thiophene. Molecular orbital calculations would be consistent with the concept of activation through a diol-epoxide mechanism and offers an explanation for the reduced genotoxicity of the sulfone via this mechanism. These genotoxicity studies support the concern that sulfur isosters of established carcinogenic polycyclic aromatic hydrocarbons could themselves be toxic. 21 refs., 2 figs., 3 tabs.

  11. Synergism between Airborne Singlet Oxygen and a Trisubstituted Olefin Sulfonate for the Inactivation of Bacteria

    PubMed Central

    2015-01-01

    The reactivity of a trisubstituted alkene surfactant (8-methylnon-7-ene-1 sulfonate, 1) to airborne singlet oxygen in a solution containing E. coli was examined. Surfactant 1 was prepared by a Strecker-type reaction of 9-bromo-2-methylnon-2-ene with sodium sulfite. Submicellar concentrations of 1 were used that reacted with singlet oxygen by an “ene” reaction to yield two hydroperoxides (7-hydroperoxy-8-methylnon-8-ene-1 sulfonate and (E)-8-hydroperoxy-8-methylnon-6-ene-1 sulfonate) in a 4:1 ratio. Exchanging the H2O solution for D2O where the lifetime of solution-phase singlet oxygen increases by 20-fold led to an ∼2-fold increase in the yield of hydroperoxides pointing to surface activity of singlet oxygen with the surfactant in a partially solvated state. In this airborne singlet oxygen reaction, E. coli inactivation was monitored in the presence and absence of 1 and by a LIVE/DEAD cell permeabilization assay. It was shown that the surfactant has low dark toxicity with respect to the bacteria, but in the presence of airborne singlet oxygen, it produces a synergistic enhancement of the bacterial inactivation. How the ene-derived surfactant hydroperoxides can provoke 1O2 toxicity and be of general utility is discussed. PMID:24611688

  12. Studies of the condensation of sulfones with ketones and aldehydes.

    PubMed

    Garst, Michael E; Dolby, Lloyd J; Esfandiari, Shervin; Okrent, Rachel A; Avey, Alfred A

    2006-01-20

    [reaction: see text] The condensation of ketones or aldehydes with sulfones was shown to give a variety of products. Condensation of 2-methylcyclohexanone with dimethyl sulfone using potassium t-butoxide as base gave useful yields of 1,2-dimethylenecyclohexane. Under the same conditions, cycloheptanone, 3-methyl-2-butanone, and 2-butanone were converted to dienes. Remarkably, these reaction conditions converted acetophenone into p-terphenyl (10%) and (E)-1,4-diphenyl-3-penten-1-one (44%). Propiophenone was converted to 2'-methyl-p-terphenyl (61%). Using alpha-tetralone produced 1-methynaphthalene and naphthalene. No reaction took place with beta-tetralone. Using diethyl sulfone with alpha-tetralone lead to pure naphthalene. Condensation of isobutyraldehyde and dimethyl sulfone using potassium t-butoxide gave isoprene in low yield. Using benzaldehyde and benzyl phenyl sulfone in N,N-dimethylacetamide gave 1,2-diphenyl-1-phenylsulfonylethylene, N,N-dimethylcinnamide, and a complex condensation product. Only 1,2-diphenyl-1-phenylsulfonylethylene was obtained when the solvent was THF. PMID:16408963

  13. A steroidogenic pathway for sulfonated steroids: the metabolism of pregnenolone sulfate.

    PubMed

    Neunzig, J; Sánchez-Guijo, A; Mosa, A; Hartmann, M F; Geyer, J; Wudy, S A; Bernhardt, R

    2014-10-01

    In many tissues sulfonated steroids exceed the concentration of free steroids and recently they were also shown to fulfill important physiological functions. While it was previously demonstrated that cholesterol sulfate (CS) is converted by CYP11A1 to pregnenolone sulfate (PregS), further conversion of PregS has not been studied in detail. To investigate whether a steroidogenic pathway for sulfonated steroids exists similar to the one described for free steroids, we examined the interaction of PregS with CYP17A1 in a reconstituted in-vitro system. Difference spectroscopy revealed a Kd-value of 74.8±4.2μM for the CYP17A1-PregS complex, which is 2.5-fold higher compared to the CYP17A1-pregnenolone (Preg) complex. Mass spectrometry experiments proved for the first time that PregS is hydroxylated by CYP17A1 at position C17, identically to pregnenolone. A higher Km- and a lower kcat-value for CYP17A1 using PregS compared with Preg were observed, indicating a 40% reduced catalytic efficiency when using the sulfonated steroid. Furthermore, we analyzed whether the presence of cytochrome b5 (b5) has an influence on the CYP17A1 dependent conversion of PregS, as was demonstrated for Preg. Interestingly, with 17OH-PregS no scission of the 17,20-carbon-carbon bond occurs, when b5 is added to the reconstituted in-vitro system, while b5 promotes the formation of DHEA from 17OH-Preg. When using human SOAT-HEK293 cells expressing CYP17A1 and CPR, we could confirm that PregS is metabolized to 17OH-PregS, strengthening the potential physiological meaning of a pathway for sulfonated steroids. PMID:25038322

  14. From thiol to sulfonic acid: modeling the oxidation pathway of protein thiols by hydrogen peroxide.

    PubMed

    van Bergen, Laura A H; Roos, Goedele; De Proft, Frank

    2014-08-01

    Hydrogen peroxide is a natural oxidant that can oxidize protein thiols (RSH) via sulfenic acid (RSOH) and sulfinic acid (RSO2H) to sulfonic acid (RSO3H). In this paper, we study the complete anionic and neutral oxidation pathway from thiol to sulfonic acid. Reaction barriers and reaction free energies for all three oxidation steps are computed, both for the isolated substrates and for the substrates in the presence of different model ligands (CH4, H2O, NH3) mimicking the enzymatic environment. We found for all three barriers that the anionic thiolate is more reactive than the neutral thiol. However, the assistance of the environment in the neutral pathway in a solvent-assisted proton-exchange (SAPE) mechanism can lower the reaction barrier noticeably. Polar ligands can decrease the reaction barriers, whereas apolar ligands do not influence the barrier heights. The same holds for the reaction energies: they decrease (become more negative) in the presence of polar ligands whereas apolar ligands do not have an influence. The consistently negative consecutive reaction energies for the oxidation in the anionic pathway when going from thiolate over sulfenic and sulfinic acid to sulfonic acid are in agreement with biological reversibility. PMID:25036614

  15. Development and evaluation of sulfonated polysulfone membranes for the zinc-ferricyanide battery

    NASA Astrophysics Data System (ADS)

    Arnold, C., Jr.; Assink, R. A.

    1985-03-01

    The successful commercialization of the zinc/ferricyanide battery being developed by Lockheed depends in part on the availability of an inexpensive, chemically stable membrane. Other essential membrane properties include low area resistivity (1 - 5 (UC OMEGA) cm(2)) and a low rate of iron permeation (4 x 10(-5) millimoles Fe(cm (2))h). A cast membrane which contained one sulfonate group per repeating unit in th backbone exhibited good stability in the alkaline ferricyanide electrolyte and satisfied the membrane requirements cited above. In ongoing single cell cycling tests, average energy efficiencies of 77% were achieved over 85 charge discharge cycles with this membrane. If sulfonate polysulfone membranes can be mass produced by extrusion, they can be considered as viable candidates to replace the expensive perfluorsulfonate membranes that were used to demonstrate the technical feasibility of the zinc/ferricyanide battery. The feasibility of preparing composite sulfonated polysulfone membranes by impregnation of microporous PTFE was also demonstrated. The manufacture of composite membranes should be possible using chemical coating equipment.

  16. Efficient and selective adsorption of multi-metal ions using sulfonated cellulose as adsorbent.

    PubMed

    Dong, Cuihua; Zhang, Fulong; Pang, Zhiqiang; Yang, Guihua

    2016-10-20

    Contamination of heavy metal in wastewater has caused great concerns on human life and health. Developing an efficient material to eliminate the heavy metal ions has been a popular topic in recent years. In this work, sulfonated cellulose (SC) was explored as efficient adsorbent for metal ions in solution. Thermo gravimetric analyzer (TGA), X-ray diffraction (XRD) and Fourier-transform infrared spectrometer (FTIR) first analyzed the characterizations of SC. Subsequently, effects of solution pH, adsorbent loading, temperature and initial metal ion concentration on adsorption performance were investigated. The results showed that sulfonated modification of cellulose could decrease the crystallinity and thermostability of cellulose. Due to its excellent performance of adsorption to metal ions, SC could reach adsorption equilibrium status within as short as 2min. In multi-component solution, SC can orderly removes Fe(3+), Pb(2+) and Cu(2+) with excellent selectivity and high efficiency. In addition, SC is a kind of green and renewable adsorbent because it can be easily regenerated by treatment with acid or chelating liquors. The mechanism study shows that the sulfonic group play a major role in the adsorption process. PMID:27474562

  17. Synergistic effects of mixing sulfone and ionic liquid as safe electrolytes for lithium sulfur batteries.

    PubMed

    Liao, Chen; Guo, Bingkun; Sun, Xiao-Guang; Dai, Sheng

    2015-01-01

    A strategy of mixing both an ionic liquid and sulfone is reported to give synergistic effects of reducing viscosity, increasing ionic conductivity, reducing polysulfide dissolution, and improving safety. The mixtures of ionic liquids and sulfones also show distinctly different physicochemical properties, including thermal properties and crystallization behavior. By using these electrolytes, lithium sulfur batteries assembled with lithium and mesoporous carbon composites show a reversible specific capacity of 1265 mAh g(-1) (second cycle) by using 40 % 1.0 M lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) in N-methyl-N-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide with 60 % 1.0 M LiTFSI in methylisopropylsulfone in the first cycle. This capacity is slightly lower than that obtained in pure 1.0 M LiTFSI as the sulfone electrolyte; however, it exhibits excellent cycling stability and remains as high as 655 mAh g(-1) even after 50 cycles. This strategy provides a method to alleviate polysulfide dissolution and redox shuttle phenomena, at the same time, with improved ionic conductivity. PMID:25427945

  18. Effect of ionic additives on the elution of sodium aryl sulfonates in supercritical fluid chromatography.

    PubMed

    Zheng, J; Taylor, L T; Pinkston, J David; Mangels, M L

    2005-08-01

    Addition of a small amount of polar solvent (i.e., modifier) to CO2 in packed column supercritical fluid chromatography (SFC) has shown major improvements in both polar analyte solubility and interaction of the polar analyte with the stationary phase. Recently, the addition of an ionic component (i.e., additive) to the primary modifier by one of us has been shown to extend even further the application of SFC to polar analytes. In this work, the effect of various ionic additives on the elution of ionic compounds, such as sodium 4-dodecylbenzene sulfonate and sodium 4-octylbenene sulfonate, has been studied. The additives were lithium acetate, ammonium acetate, tetramethylammonium acetate, tetrabutylammonium acetate, and ammonium chloride dissolved in methanol. Three stationary phases with different degrees of deactivation were considered: conventional cyanopropyl, deltabond cyanopropyl, and bare silica. The effect of additive concentration and additive functionality on analyte retention was investigated. Sodium 4-dodecylbenzene sulfonate was successfully eluted using all the additives with good peak shape under isocratic/isobaric/isothermal conditions. Different additives, however, yielded different retention times and in some cases different peak shapes. PMID:16035365

  19. A potential new metabolite of gamma-hydroxybutyrate: sulfonated gamma-hydroxybutyric acid.

    PubMed

    Hanisch, Stephanie; Stachel, Nicole; Skopp, Gisela

    2016-03-01

    Detection of gamma-hydroxybutyric acid (GHB) became crucial in many clinical and forensic settings due to its increasing use for recreational purposes and drug-facilitated sexual assault. Its narrow window of detection of about 3-12 h in urine represents a major problem. Analogous to ethyl glucuronide, the recently identified GHB-glucuronide exhibits a longer window of detection than the parent drug. It appeared reasonable that a sulfonated metabolite of GHB (GHB-SUL) will also be formed. Due to the lack of an appropriate standard, GHB was incubated with a human liver cytosolic fraction to produce GHB-SUL. Following development of a liquid chromatography/tandem mass spectrometry (LC-MS/MS) assay to measure GHB and GHB-SUL, authentic urine samples (n = 5) were tested for GHB-SUL. These investigations revealed detectable signals of both GHB and GHB-SUL, strongly indicating that GHB is not only glucuronidated but also sulfonated. Given that sulfonated metabolites generally have longer half-life times than the corresponding free drugs, GHB-SUL may serve as a biomarker of GHB misuse along with its glucuronide. PMID:26210636

  20. ER Suspensions of Sulfonated Poly(Styrene-CO-Divinylbenzene) Particles

    NASA Astrophysics Data System (ADS)

    Kawakami, Toshihiro; Aizawa, Ryuji; Konishi, Masayoshi; Asako, Yoshinobu

    Two ER suspensions (ERF1 and ERF2) containing highly sulfonated poly(styrene-co-divinylbenzene) particles (ERP) were newly prepared. The ERP concentration was 20 wt% in ERF1 and 40 wt% in ERF2. The ER properties of the suspensions were investigated in view of applications to practical devices. The investigated properties were zero-field viscosity, dispersion stability, induced shear stress, current density, response time, shear rate and temperature dependence of the induced shear stress and current density, response time, shear rate and temperature dependence of the induced shear stress and the current density. electrical durability. In the results, it was found that ERF1 and ERF2 had a very high potential for practical applicatons. The remarkable characteristic of ERF1 was the very low zero-field viscosity of 35 mPa·s at 25°C. The remarkable characteristic of ERF2 was very large induced shear stress and under applying DC 4 kV/mm at 25°C, the induced shear stress was 5.1 kPa. As an application example, the ERFs can be efficiently used for an ER Cutting Machine incorporating variable speed rodless cylinders. The machine has worked smoothly for one and a half years, although the characteristic of control slightly changed.

  1. Synthesis and characterization of sulfonated poly (arylene ether sulfone) copolymers via direct copolymerization: Candidates for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Harrison, William Lamont

    A designed series of directly copolymerized homo- and disulfonated copolymers containing controlled degrees of pendant sulfonic acid groups have been synthesized via nucleophilic step polymerization. Novel sulfonated poly (arylene ether sulfone) copolymers using 4,4'-bisphenol A, 4,4'-biphenol, hexafluorinated (6F) bisphenol AF, and hydroquinone, respectively, with dichlorodiphenyl sulfone (DCDPS) and 3,3'-disodiumsulfonyl-4,4'-dichlorodiphenylsulfone (SDCDPS) were investigated. Molar ratios of DCDPS and SDCDPS were systematically varied to produce copolymers of controlled compositions, which contained up to 70 mol% of disulfonic acid moiety. The goal is to identify thermally, hydrolytically, and oxidatively stable high molecular weight, film-forming, ductile ion conducting copolymers, which had properties desirable for proton exchange membranes (PEM) in fuel cells. Commercially available bisphenols were selected to produce cost effective alternative PEMs. Partially aliphatic bisphenol A and hexafluorinated (6F) bisphenol AF produced amorphous copolymers with different thermal oxidative and surface properties. Biphenol and hydroquinone was utilized to produce wholly aromatic copolymers. The sulfonated copolymers were prepared in the sodium-salt form and converted to the acid moiety via two different methodologies and subsequently investigated as proton exchange membranes for fuel cells. Hydrophilicity increased with the level of disulfonation, as expected. Moreover, water sorption increased with increasing mole percent incorporation of SDCDPS. The copolymers' water uptake was a function of both bisphenol structure and degree of disulfonation. Furthermore, the acidification procedures were shown to influence the Tg values, water uptake, and conductivity of the copolymers. Atomic force microscopy (AFM) in the tapping mode confirmed that the morphology of the copolymers could be designed to display nanophase separation in the hydrophobic and hydrophilic (sulfonated

  2. Mechanistic Aspects of the Palladium-Catalyzed Isomerization of Allenic Sulfones to 1-Arylsulfonyl 1,3-Dienes.

    PubMed

    Hampton, Carissa S; Harmata, Michael

    2016-06-01

    When an allenic sulfone is treated under palladium catalysis in the presence of a weak acid, isomerization to a 1-arylsulfonyl 1,3-diene occurs. Investigations of the mechanistic aspects of this isomerization were performed, leading to the mechanism proposed herein. Some further studies of reaction parameters are reported. PMID:27127922

  3. Analysis of metolachlor ethane sulfonic acid chirality in groundwater: A tool for dating groundwater movement in agricultural settings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical chirality of pesticides can be a useful tool for studying environmental processes. The chiral forms of metolachlor ethane sulfonic acid (MESA), an abundant metabolite of metolachlor, and metolachlor were examined over a 6 year period in groundwater and a groundwater-fed stream in a riparia...

  4. HEPATIC GENE EXPRESSION PROFILING IN PERFLUOROHEXANE SULFONATE-EXPOSED WILD-TYPE AND PPARα-NULL MICE.

    EPA Science Inventory

    Perfluorohexane sulfonate (PFHxS) is one member of a group ofperfluoroakyl acids (PFAAs) presently recognized as widespread environmental contaminants. Like other PFAAs, PFHxS is also commonly found in human serum. Although PFHxS is presumed to be an activator of peroxisome proli...

  5. A FACILE ONE-POT SYNTHESIS OF β-KETO SULFONES FROM KETONES UNDER SOLVENT-FREE CONDITIONS

    EPA Science Inventory

    An easy solvent-free method is described for the conversion of ketones into β-keto sulfones in high yields that involves in situ generation of α-tosyloxyketones followed by nucleophilic substitution with sodium arene sulfinate in presence of tetra-butylammonium bromide at ...

  6. Sulfonation Pathway Inhibitors Block Reactivation of Latent HIV-1

    PubMed Central

    Murry, Jeffrey P.; Godoy, Joseph; Mukim, Amey; Swann, Justine; Bruce, James W.; Ahlquist, Paul; Bosque, Alberto; Planelles, Vicente; Spina, Celsa A.; Young, John A. T.

    2015-01-01

    Long-lived pools of latently infected cells are a significant barrier to the development of a cure for HIV-1 infection. A better understanding of the mechanisms of reactivation from latency is needed to facilitate the development of novel therapies that address this problem. Here we show that chemical inhibitors of the sulfonation pathway prevent virus reactivation, both in latently infected J-Lat and U1 cell lines and in a primary human CD4+ T cell model of latency. In each of these models, sulfonation inhibitors decreased transcription initiation from the HIV-1 promoter. These inhibitors block transcription initiation at a step that lies downstream of nucleosome remodeling and affects RNA polymerase II recruitment to the viral promoter. These results suggest that the sulfonation pathway acts by a novel mechanism to regulate efficient virus transcription initiation during reactivation from latency, and further that augmentation of this pathway could be therapeutically useful. PMID:25310595

  7. Palladium-catalyzed direct α-arylation of methyl sulfones with aryl bromides.

    PubMed

    Zheng, Bing; Jia, Tiezheng; Walsh, Patrick J

    2013-04-01

    A direct and efficient approach for palladium-catalyzed arylation of aryl and alkyl methyl sulfones with aryl bromides has been developed. The catalytic system affords arylated sulfones in good to excellent yields (73-90%). PMID:23517309

  8. Synthesis and characterization of sulfonated single-walled carbon nanotubes and their performance as solid acid catalyst

    SciTech Connect

    Yu Hao Jin Yuguang; Li Zhili; Peng Feng Wang Hongjuan

    2008-03-15

    Single-walled carbon nanotubes (SWCNTs) were treated with sulfuric acid at 300 deg. C to synthesize sulfonated SWCNTs (s-SWCNTs), which were characterized by electron microscopy, infrared, Raman and X-ray photoelectron spectroscopy, and thermo analysis. Compared with activated carbon, more sulfonic acid groups can be introduced onto the surfaces of SWCNTs. The high degree ({approx}20 wt%) of surface sulfonation led to hydrophilic sidewalls that allows the SWCNTs to be uniformly dispersed in water and organic solvents. The high surface acidity of s-SWCNTs was demonstrated by NH{sub 3} temperature-programmed desorption technique and tested by an acetic acid esterification reaction catalyzed by s-SWCNTs. The results show that the water-dispersive s-SWCNTs are an excellent solid acid catalyst and demonstrate the potential of SWCNTs in catalysis applications. - Graphical abstract: Sulfonated SWCNTs with 20 wt% -SO{sub 2}OH groups were prepared by a high-temperature H{sub 2}SO{sub 4} process, which transformed the hydrophobic surface of pristine SWCNTs to a hydrophilic surface and provided an excellent performance as solid acid catalyst.

  9. Chronic perfluorooctane sulfonate (PFOS) exposure induces hepatic steatosis in zebrafish.

    PubMed

    Cheng, Jiangfei; Lv, Suping; Nie, Shangfei; Liu, Jing; Tong, Shoufang; Kang, Ning; Xiao, Yanyan; Dong, Qiaoxiang; Huang, Changjiang; Yang, Dongren

    2016-07-01

    Perfluorooctane sulfonate (PFOS), one persistent organic pollutant, has been widely detected in the environment, wildlife and human. Currently few studies have documented the effects of chronic PFOS exposure on lipid metabolism, especially in aquatic organisms. The underlying mechanisms of hepatotoxicity induced by chronic PFOS exposure are still largely unknown. The present study defined the effects of chronic exposure to low level of PFOS on lipid metabolism using zebrafish as a model system. Our findings revealed a severe hepatic steatosis in the liver of males treated with 0.5μM PFOS as evidenced by hepatosomatic index, histological assessment and liver lipid profiles. Quantitative PCR assay further indicated that PFOS significantly increase the transcriptional expression of nuclear receptors (nr1h3, rara, rxrgb, nr1l2) and the genes associated with fatty acid oxidation (acox1, acadm, cpt1a). In addition, chronic PFOS exposure significantly decreased liver ATP content and serum level of VLDL/LDL lipoprotein in males. Taken together, these findings suggest that chronic PFOS exposure induces hepatic steatosis in zebrafish via disturbing lipid biosynthesis, fatty acid β-oxidation and excretion of VLDL/LDL lipoprotein, and also demonstrate the validity of using zebrafish as an alternative model for PFOS chronic toxicity screening. PMID:27108203

  10. Perfluorooctane sulfonate (PFOS) induced embryotoxicity and disruption of cardiogenesis.

    PubMed

    Cheng, Wei; Yu, Zhuo; Feng, Lixin; Wang, Yan

    2013-08-01

    Prenatal exposure to perfluorooctane sulfonate (PFOS) is correlated with birth defects and adverse health effects. However, the mechanisms remain largely unknown. In current study, the embryonic stem cell test (EST) was performed to evaluate the embryotoxicity of PFOS, and embryonic stem cells (ESCs)-derived cardiomyocytes were used as a model of the early stages of heart development to determine the developmental toxicity of PFOS. One validated endpoint and three molecular endpoints were observed to ensure accurate evaluation of toxicity. According to the criteria of the EST, PFOS was classified as weak embryotoxic. In addition, a cascade of genes related to normal cardiac development was examined at three different time points to monitor cardiogenesis. We found that PFOS significantly interfered with gene expression during cardiogenesis, especially on Nkx2.5 and Myl4. Further, PFOS reduced ATP production in ESCs-derived cardiomyocytes, together with PFOS induced apoptosis, could explain the reduction in beating ability. PFOS-induced reactive oxygen species (ROS) accumulated within cells, which was accompanied by an interfering expression of apoptosis-related genes, ultimately leading to apoptosis. In conclusion, PFOS altered the expression of crucial genes, reduced ATP production, induced ROS, and stimulated apoptosis during the early stages of cardiogenesis; these effects may result in poor developmental outcomes. PMID:23562911

  11. Degradation of sodium dodecylbenzene sulfonate in water by ultrasonic irradiation.

    PubMed

    Manousaki, Eleni; Psillakis, Elefteria; Kalogerakis, Nicolas; Mantzavinos, Dionissios

    2004-10-01

    The potential of using ultrasonic irradiation for the removal of sodium dodecylbenzene sulfonate (SDBS) from aqueous solutions has been investigated. Experiments were performed at initial concentrations of 15, 30 and 100 mgl(-1), ultrasonic frequencies of 20 and 80 kHz, applied power values of 45, 75 and 150 W and liquid bulk temperatures of 20, 40 and 60 degrees C. At the conditions in question, SDBS conversion was found to decrease with increasing temperature and initial solute concentration and decreasing power and frequency. Investigations using the radical scavengers 1-butanol and KBr revealed that SDBS degradation proceeds through radical reactions occurring predominately at the bubble-liquid interface and, to a lesser extent, in the liquid bulk. Addition of NaCl or H(2)O(2) had little or even an adverse effect on SDBS conversion. Conversely, addition of Fe(2+) either alone or in conjunction with H(2)O(2) (Fenton reagent) had a positive effect on degradation. Finally, shake flask tests with activated sludge were performed to assess the aerobic biodegradability before and after sonochemical treatment. At the conditions under consideration, the use of ultrasound enhanced the aerobic degradability of the substrate in question. PMID:15350427

  12. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Consoer, Daniel M; Hoffman, Alex D; Fitzsimmons, Patrick N; Kosian, Patricia A; Nichols, John W

    2016-03-01

    Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma and either urine or expired water. The data were then analyzed using a 2-compartment clearance-volume model. Renal and branchial clearance rates (mL/d/kg) determined for all experiments averaged 19% and 81% of total clearance, respectively. Expressed as mean values for all experiments, the steady-state volume of distribution was 277 mL/kg and the terminal half-life was 86.8 d. Additional animals were exposed to PFOS in water, resulting in an average calculated branchial uptake efficiency of 0.36%. The renal clearance rate determined in the present study is approximately 75 times lower than that determined in earlier studies with perfluorooctanoate (PFOA). Previously, it was suggested that PFOA is a substrate for membrane transporters in the trout kidney. The present study suggests that glomerular filtration may be sufficient to explain the observed renal clearance rate for PFOS, although a role for membrane transporters cannot be ruled out. These findings demonstrate that models developed to predict the bioaccumulation of perfluoroalkyl acids by fish must account for differences in renal clearance of individual compounds. Environ Toxicol Chem 2016;35:717-727. © 2015 SETAC. PMID:26332333

  13. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

    1997-01-01

    Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

  14. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  15. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  16. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  17. 40 CFR 721.10437 - Sulfonic acid, linear xylene alkylate, mono, sodium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonic acid, linear xylene alkylate... Significant New Uses for Specific Chemical Substances § 721.10437 Sulfonic acid, linear xylene alkylate, mono... chemical substances identified generically as sulfonic acid, linear xylene alkylate, mono, sodium...

  18. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  19. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... Substances § 721.10045 Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  20. 40 CFR 721.10487 - Alkylbenzenes sulfonic acids, metal salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkylbenzenes sulfonic acids, metal... Specific Chemical Substances § 721.10487 Alkylbenzenes sulfonic acids, metal salts (generic). (a) Chemical... as alkylbenzenes sulfonic acids, metal salts (PMNs P-04-599, P-04-600, P-04-605, and P-04-606)...

  1. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  2. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated sulfonated diphenyl oxide... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and...

  3. 40 CFR 721.644 - Amines, C12-14-tert-alkyl, sulfonates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, C12-14-tert-alkyl, sulfonates... Substances § 721.644 Amines, C12-14-tert-alkyl, sulfonates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amines, C12-14-tert-alkyl, sulfonates...

  4. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  5. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  6. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  7. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  8. 40 CFR 721.9620 - Aromatic sulfonic acid compound with amine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid compound with... Specific Chemical Substances § 721.9620 Aromatic sulfonic acid compound with amine. (a) Chemical substance... aromatic sulfonic acid compound with amine (PMN P-93-832) is subject to reporting under this section...

  9. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  10. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  11. 40 CFR 721.10474 - Substituted amino ethane sulfonic acid salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Substituted amino ethane sulfonic acid... Specific Chemical Substances § 721.10474 Substituted amino ethane sulfonic acid salt (generic). (a... generically as substituted amino ethane sulfonic acid salt (PMN P-04-107) is subject to reporting under...

  12. 40 CFR 721.10633 - Aromatic sulfonic acid amino azo dye salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aromatic sulfonic acid amino azo dye... Specific Chemical Substances § 721.10633 Aromatic sulfonic acid amino azo dye salts (generic). (a) Chemical... as aromatic sulfonic acid amino azo dye salts (PMN P-12-276) is subject to reporting under...

  13. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  14. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  15. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  16. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  17. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  18. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  19. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  20. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  1. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  2. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfonated-copper phthalocyanine salt... Significant New Uses for Specific Chemical Substances § 721.9674 Sulfonated-copper phthalocyanine salt of a... chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane...

  3. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  4. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  5. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  6. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  7. 40 CFR 721.5450 - α-Olefin sulfonate, sodium salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false α-Olefin sulfonate, sodium salt. 721... Substances § 721.5450 α-Olefin sulfonate, sodium salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as α-olefin sulfonate, sodium...

  8. 40 CFR 721.10564 - Mixed amino diaryl sulfone isomers (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed amino diaryl sulfone isomers... Specific Chemical Substances § 721.10564 Mixed amino diaryl sulfone isomers (generic). (a) Chemical... as mixed amino diaryl sulfone isomers (PMN P-08-39) is subject to reporting under this section...

  9. 40 CFR 721.10564 - Mixed amino diaryl sulfone isomers (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixed amino diaryl sulfone isomers... Specific Chemical Substances § 721.10564 Mixed amino diaryl sulfone isomers (generic). (a) Chemical... as mixed amino diaryl sulfone isomers (PMN P-08-39) is subject to reporting under this section...

  10. Reaction kinetics of free fatty acids esterification in palm fatty acid distillate using coconut shell biochar sulfonated catalyst

    NASA Astrophysics Data System (ADS)

    Hidayat, Arif; Rochmadi, Wijaya, Karna; Budiman, Arief

    2015-12-01

    Recently, a new strategy of preparing novel carbon-based solid acids has been developed. In this research, the esterification reactions of Palm Fatty Acid Distillate (PFAD) with methanol, using coconut shell biochar sulfonated catalyst from biomass wastes as catalyst, were studied. In this study, the coconut shell biochar sulfonated catalysts were synthesized by sulfonating the coconut shell biochar using concentrated H2SO4. The kinetics of free fatty acid (FFA) esterification in PFAD using a coconut shell biochar sulfonated catalyst was also studied. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%w, and reaction temperature of 60°C. The proposed kinetic model shows a reversible second order reaction and represents all the experimental data satisfactorily, providing deeper insight into the kinetics of the reaction.

  11. Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

    PubMed

    Rayne, Sierra; Forest, Kaya

    2016-10-14

    In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems. PMID:27389973

  12. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... produced by chloro-sulfonation of a carbon tetrachloride solution of polyethylene with chlorine and...) Chlorine not to exceed 25 percent by weight. (2) Sulfur not to exceed 1.15 percent by weight. (3) Molecular... “Chlorine and Bromine—Coulometric Titration Method by Aminco Chloridometer,” “Hypolon ® Synthetic...

  13. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... polyethylene with chlorine and sulfuryl chloride. (b) Ethylene polymer, chloro-sulfonated shall meet the following specifications: (1) Chlorine not to exceed 25 percent by weight. (2) Sulfur not to exceed 1.15... specifications in this paragraph (b), titled “Chlorine and Bromine—Coulometric Titration Method by...

  14. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... polyethylene with chlorine and sulfuryl chloride. (b) Ethylene polymer, chloro-sulfonated shall meet the following specifications: (1) Chlorine not to exceed 25 percent by weight. (2) Sulfur not to exceed 1.15... specifications in this paragraph (b), titled “Chlorine and Bromine—Coulometric Titration Method by...

  15. One-pot, three-component arylalkynyl sulfone synthesis.

    PubMed

    Chen, C Chun; Waser, Jerome

    2015-02-01

    A one-pot three-component protocol for the preparation of arylsulfonyl alkynes through the reaction of ethynyl-benziodoxolone (EBX) reagents, DABSO (DABCO·SO2), and either organomagnesium reagents or aryl iodides with a palladium catalyst is reported. A broad range of aryl and heteroarylalkynyl sulfones were obtained in 46-85% overall yield. PMID:25633719

  16. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyphenylene sulfone resins. 177.2500 Section 177.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only...

  17. 21 CFR 177.2500 - Polyphenylene sulfone resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyphenylene sulfone resins. 177.2500 Section 177.2500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only...

  18. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sulfonic acid has the empirical formula CF3SO3H (CAS Reg. No. 1493-13-6). The catalyst (Trifluoromethane... catalyst meets the following specifications: Appearance, Clear liquid. Color, Colorless to amber... esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous...

  19. 21 CFR 173.395 - Trifluoromethane sulfonic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Trifluoromethane sulfonic acid. 173.395 Section 173.395 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Specific Usage Additives §...

  20. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer,...

  1. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use § 177.2210 Ethylene polymer,...

  2. Synthesis and characterization of nanostructured sulfonated polyimides for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Zou, Lijun

    Sulfonated polyimides (SPI) are considered to be good candidates for proton exchange membranes (PEMs) since they exhibit high strength, good film-forming ability, chemical resistance, thermal stability, and, in their hydrated state, relatively high proton conductivity. Despite intense research in the area of SPIs, fundamental investigations of hydrophilic/hydrophobic phase segregation and studies of humidity dependent morphologies are scarce. In an effort to influence the order and distribution of ionic groups in rigid-rod SPIs and to understand the interrelationships between morphology, hydration and proton conductivity, two novel model systems of SPI polymers containing hydrophobic polysiloxane (SPI-PSX) and hydrophilic silica nanoparticles (SPI-Si) were developed. The first model system of sulfonated polyimide containing hydrophobic polysiloxane segmented copolymers was prepared by a one-pot synthesis. SPI-PSX materials were evaluated using 1H NMR, size-exclusion chromatography. The presence of ion-containing diamines in the reaction mixture was found to inhibit stoichiometric incorporation of hydrophobic siloxane segments. Siloxane segments were found to lower the thermal stability of the polyimide host. Equilibrium water sorption studies of free standing films of copolymers with and without siloxane segments show that the presence of siloxane segments does not interfere with water swelling, which suggests a microphase-segregated morphology may exist. TEM and SAXS analyses show evidence of phase-segregation in sulfonated polyimides and reveal that siloxane segments strongly affect ionic clustering. However, proton conductivity only changes slightly when polysiloxane segments are incorporated. Sulfonated polyimides containing hydrophilic silica nanoparticles is our second model system developed for stabilizing the dispersed morphologies to promote proton conductivity. SPI-Si nanocomposites were prepared by a pre-polymer of anhydride-terminated sulfonated

  3. Isotopic Measurements of Organic Sulfonates From The Murchison Meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, G. W.; Chang, S.; DeVincenzi, Donald L. (Technical Monitor)

    1995-01-01

    Organic sulfonates and phosphonates have been extracted from the Murchison meteorite for stable isotope measurements. Preliminary stable isotope measurements of individual alkyl sulfonates, R-SO3H (R=C(sub n)H(sub 2n+l)), are shown. These compounds were found in aqueous extracts of Murchison. Both groups show trends similar to other homologous series of organic compounds indigenous to Murchison. Molecular abundances decrease with increasing carbon number, and all possible isomers at each carbon number (through C-4) are present. Carbon isotope measurements of the sulfonates show a decrease in the C-13/C-12 ratio with increasing carbon number. The overall objectives of this project are to obtain dime element carbon, hydrogen, and sulfur - intramolecular isotopic analyses of individual sulfonates, and isotopic measurement of carbon and hydrogen of the phosphonates as a group. The Murchison meteorite is the best characterized carbonaceous chondrite with respect to organic chemistry. The finding of organic sulfonates and phosphonates in Murchison is of interest because they are the first well-characterized series of sulfur and phosphorus containing organic compounds found in meteorites. Also, meteorites, comets, and interplanetary dust particles may have been involved in chemical evolution on the early Earth. Because of the critical role of organic phosphorus and sulfur in all living systems, it is particularly interesting to see examples of abiotic syntheses of these classes of compounds. The study of the isotopic composition of the sulfonates and phosphonates can yield insight into their possible interstellar origin as well as their mechanisms of synthesis in the early solar system. Previous isotopic analyses of other classes of organic compounds indigenous to meteorites, e.g., amino acids, carboxylic acids, and hydrocarbons indicate the possibility that interstellar molecules were incorporated into meteorite parent bodies. In these compounds the ratios of heavy to

  4. Fibrillization of Human Tau Is Accelerated by Exposure to Lead via Interaction with His-330 and His-362

    PubMed Central

    Zhu, Hai-Li; Meng, Sheng-Rong; Fan, Jun-Bao; Chen, Jie; Liang, Yi

    2011-01-01

    Background Neurofibrillary tangles, mainly consisted of bundles of filaments formed by the microtubule-associated protein Tau, are a hallmark of Alzheimer disease. Lead is a potent neurotoxin for human being especially for the developing children, and Pb2+ at high concentrations is found in the brains of patients with Alzheimer disease. However, it has not been reported so far whether Pb2+ plays a role in the pathology of Alzheimer disease through interaction with human Tau protein and thereby mediates Tau filament formation. In this study, we have investigated the effect of Pb2+ on fibril formation of recombinant human Tau fragment Tau244–372 and its mutants at physiological pH. Methodology/Principal Findings As revealed by thioflavin T and 8-anilino-1-naphthalene sulfonic acid fluorescence, the addition of 5–40 µM Pb2+ significantly accelerates the exposure of hydrophobic region and filament formation of wild-type Tau244–372 on the investigated time scale. As evidenced by circular dichroism and Fourier transform infrared spectroscopy, fibrils formed by wild-type Tau244–372 in the presence of 5–40 µM Pb2+ contain more β-sheet structure than the same amount of fibrils formed by the protein in the absence of Pb2+. However, unlike wild-type Tau244–372, the presence of 5–40 µM Pb2+ has no obvious effects on fibrillization kinetics of single mutants H330A and H362A and double mutant H330A/H362A, and fibrils formed by such mutants in the absence and in the presence of Pb2+ contain similar amounts of β-sheet structure. The results from isothermal titration calorimetry show that one Pb2+ binds to one Tau monomer via interaction with His-330 and His-362, with sub-micromolar affinity. Conclusions/Significance We demonstrate for the first time that the fibrillization of human Tau protein is accelerated by exposure to lead via interaction with His-330 and His-362. Our results suggest the possible involvement of Pb2+ in the pathogenesis of Alzheimer disease

  5. Development of a new highly conductive and thermomechanically stable complex membrane based on sulfonated polyimide/ionic liquid for high temperature anhydrous fuel cells

    NASA Astrophysics Data System (ADS)

    Deligöz, Hüseyin; Yılmazoğlu, Mesut

    The paper deals with the synthesis and characterization of a new type of acid doped highly conductive complex membrane based on sulfonated polyimide (sPI) and ionic liquid (IL) for high temperature anhydrous fuel cells. For this purpose, 2,4-diaminobenzene sulfonic acid (2,4-DABSA) is reacted with benzophenontetracarboxylic dianhydride (BTDA) to yield sulfonated poly(amic acid) (sPAA) intermediate. Subsequently, IL is added into sPAA to form an interaction between sulfonic acid and imidazolium group of IL followed by acid doping. The ionic conductivity of acid doped sPI/IL complex polymer membrane is higher than that of IL containing composite membranes reported in the literature (5.59 × 10 -2 S cm -1 at 180 °C). Furthermore, dynamic mechanical analysis (DMA) results of acid doped sPI/IL complex membrane show that the mechanical strength of the complex product is slightly changed until 350 °C due to the formation of ionic interactions between sulfonic acid groups of sPI and imidazolium groups of IL. Consequently, the ionic interaction not only provides high ionic conductivity with excellent thermomechanical properties (the storage module of 0.91 GPa at 300 °C) but also results in a positive effect in long term conductivity stability by blocking IL migration through the membrane.

  6. ANALYSIS OF SULFONATES IN AQUEOUS SAMPLES BY ION-PAIR LC/ESI-MS/MS WITH IN-SOURCE CID FOR ADDUCT PEAK ELIMINATION

    SciTech Connect

    OUYANG,S.; VAIRAVAMURTHY,M.A.

    1999-06-13

    Determination of low-molecular-weight organic sulfonates (e.g. taurine and cysteic acid) in aqueous solutions is important in many applications of biological, environmental and pharmaceutical sciences. These compounds are difficult to be determined by commonly used reversed-phase liquid chromatographic separation combined with UV-Visible detection because of their high solubility and the lack chromophoric moieties. Here the authors report a method combining ion-pair liquid chromatography and electrospray ionization tandem mass spectrometry (IPLC/ESI-MS/MS)for determining sulfonates. The ability of low-molecular-weight sulfonates to form ion-pairs with quaternary ammonium cations in aqueous solutions allowed LC separation with a C{sub 18} column. Detection of the sulfonates was accomplished with ESI-MS that lends a universal mode of mass detection for polar, water soluble compounds. An in-source collision induced dissociation (CID) was applied to eliminate the adduct peaks in mass spectra. Characteristic marker ions showed in the second stage mass spectra lent a method for identifying sulfonates.

  7. Synthesis and antimalarial activities of some furoxan sulfones and related furazans.

    PubMed

    Galli, Ubaldina; Lazzarato, Loretta; Bertinaria, Massimo; Sorba, Giovanni; Gasco, Alberto; Parapini, Silvia; Taramelli, Donatella

    2005-12-01

    Furoxan derivatives bearing a sulfone moiety at position 3 or 4 were synthesized and tested for their antimalarial action on the chloroquine-sensitive D10 and the chloroquine-resistant W2 strains of Plasmodium falciparum. The furazan analogues were considered for comparison. The most active compounds were the products in which the -SO2R groups are at the 3-position of the furoxan system. These latter substances displayed an antimalarial activity in the microM range, possibly related in part to their ability to release NO. PMID:15979766

  8. Chondrogenesis on sulfonate-coated hydrogels is regulated by their mechanical properties.

    PubMed

    Kwon, Hyuck Joon; Yasuda, Kazunori

    2013-01-01

    Many studies have demonstrated that sulfur-containing acidic groups induce chondrogenesis in vitro and in vivo. Recently, it is increasingly clear that mechanical properties of cell substrates largely influence cell differentiation. Thus, the present study investigated how mechanical properties of sulfonate-coated hydrogels influences chondrogenesis of mesenchymal stem cells (MSCs). Sulfonate-coated polyacrylamide gels (S-PAAm gels) which have the elastic modulus, E, of about 1, 15 and 150 kPa, were used in this study. MSCs cultured on the high stiffness S-PAAm gels (E=∼150 kPa) spread out with strong expression of stress fibers, while MSCs cultured on the low stiffness S-PAAm gels (E=∼1 kPa) had round shapes with less stress fibers but more cortical actins. Importantly, even in the absence of differentiation supplements, the lower stiffness S-PAAm gels led to the higher mRNA levels of chondrogenic markers such as Col2a1, Agc and Sox9 and the lower mRNA levels of an undifferentiation marker Sca1, indicating that the mechanical properties of S-PAAm gels strongly influence chondrogenesis. Blebbistatin which blocks myosin II-mediated mechanical sensing suppressed chondrogenesis induced by the low stiffness S-PAAm gels. The present study demonstrates that the soft S-PAAm gels effectively drive MSC chondrogenesis even in the absence of soluble differentiation factors and thus suggests that sulfonate-containing hydrogels with low stiffness could be a powerful tool for cartilage regeneration. PMID:23127629

  9. Low-Molecular-Weight Sulfonates, a Major Substrate for Sulfate Reducers in Marine Microbial Mats†

    PubMed Central

    Visscher, Pieter T.; Gritzer, Rachel F.; Leadbetter, Edward R.

    1999-01-01

    Several low-molecular-weight sulfonates were added to microbial mat slurries to investigate their effects on sulfate reduction. Instantaneous production of sulfide occurred after taurine and cysteate were added to all of the microbial mats tested. The rates of production in the presence of taurine and cysteate were 35 and 24 μM HS− h−1 in a stromatolite mat, 38 and 36 μM HS− h−1 in a salt pond mat, and 27 and 18 μM HS− h−1 in a salt marsh mat, respectively. The traditionally used substrates lactate and acetate stimulated the rate of sulfide production 3 to 10 times more than taurine and cysteate stimulated the rate of sulfide production in all mats, but when ethanol, glycolate, and glutamate were added to stromatolite mat slurries, the resulting increases were similar to the increases observed with taurine and cysteate. Isethionate, sulfosuccinate, and sulfobenzoate were tested only with the stromatolite mat slurry, and these compounds had much smaller effects on sulfide production. Addition of molybdate resulted in a greater inhibitory effect on acetate and lactate utilization than on sulfonate use, suggesting that different metabolic pathways were involved. In all of the mats tested taurine and cysteate were present in the pore water at nanomolar to micromolar concentrations. An enrichment culture from the stromatolite mat was obtained on cysteate in a medium lacking sulfate and incubated anaerobically. The rate of cysteate consumption by this enrichment culture was 1.6 pmol cell−1 h−1. Compared to the results of slurry studies, this rate suggests that organisms with properties similar to the properties of this enrichment culture are a major constituent of the sulfidogenic population. In addition, taurine was consumed at some of highest dilutions obtained from most-probable-number enrichment cultures obtained from stromatolite samples. Based on our comparison of the sulfide production rates found in various mats, low-molecular-weight sulfonates

  10. Improved oral absorption of cilostazol via sulfonate salt formation with mesylate and besylate

    PubMed Central

    Seo, Jae Hong; Park, Jung Bae; Choi, Woong-Kee; Park, Sunhwa; Sung, Yun Jin; Oh, Euichaul; Bae, Soo Kyung

    2015-01-01

    Objective Cilostazol is a Biopharmaceutical Classification System class II drug with low solubility and high permeability, so its oral absorption is variable and incomplete. The aim of this study was to prepare two sulfonate salts of cilostazol to increase the dissolution and hence the oral bioavailability of cilostazol. Methods Cilostazol mesylate and cilostazol besylate were synthesized from cilostazol by acid addition reaction with methane sulfonic acid and benzene sulfonic acid, respectively. The salt preparations were characterized by nuclear magnetic resonance spectroscopy. The water contents, hygroscopicity, stress stability, and photostability of the two cilostazol salts were also determined. The dissolution profiles in various pH conditions and pharmacokinetic studies in rats were compared with those of cilostazol-free base. Results The two cilostazol salts exhibited good physicochemical properties, such as nonhygroscopicity, stress stability, and photostability, which make it suitable for the preparation of pharmaceutical formulations. Both cilostazol mesylate and cilostazol besylate showed significantly improved dissolution rate and extent of drug release in the pH range 1.2–6.8 compared to the cilostazol-free base. In addition, after oral administration to rats, cilostazol mesylate and cilostazol besylate showed increases in Cmax and AUCt of approximately 3.65- and 2.87-fold and 3.88- and 2.94-fold, respectively, compared to cilostazol-free base. Conclusion This study showed that two novel salts of cilostazol, such as cilostazol mesylate and cilostazol besylate, could be used to enhance its oral absorption. The findings warrant further preclinical and clinical studies on cilostazol mesylate and cilostazol besylate at doses lower than the usually recommended dosage, so that it can be established as an alternative to the marketed cilostazol tablet. PMID:26251575

  11. Identification of Novel Polyfluorinated Ether Sulfonates as PFOS Alternatives in Municipal Sewage Sludge in China.

    PubMed

    Ruan, Ting; Lin, Yongfeng; Wang, Thanh; Liu, Runzeng; Jiang, Guibin

    2015-06-01

    A 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFAES) with the trade name F-53B, is an alternative to perfluorooctanesulfonate (PFOS) in electroplating industry that is uniquely used in China. It was developed as a mist suppressant initially in the 1970s, but the environmental behaviors and potential adverse effects of the 6:2 Cl-PFAES have only recently been investigated. In this work, the occurrence and distribution of perfluoroalkyl sulfonate (PFSA), fluorotelomer sulfonate (FTSA), and PFAES analogues were investigated in municipal sewage sludge samples collected around China. Perfluorobutane, perfluorohexane, perfluorooctane, and perfluorodecanesulfonates, 6:2 and 8:2 FTSAs, and the emerging 6:2 Cl-PFAES were detected. Moreover, 8:2 and 10:2 Cl-PFAESs were identified for the first time as new polyfluorinated contaminants using high resolution mass spectrometry. These fluorinated analytes were further quantified with the aid of commercial and laboratory-purified standards. PFOS was the predominant contaminant with a geometric mean (GM) value of 3.19 ng/g dry weight (d.w.), which was subsequently followed by 6:2 Cl-PFAES and 8:2 Cl-PFAES (GM: 2.15 and 0.50 ng/g d.w., respectively). Both 6:2 and 8:2 Cl-PFAES were positively detected as the major components in the F-53B commercial product, and discrete 6:2 Cl-PFAES/8:2 Cl-PFAES ratios in the product and sludge samples might suggest 8:2 Cl-PFAES had enhanced sorption behavior in the sludge due to the increase in hydrophobicity. PMID:25961764

  12. Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

    PubMed Central

    Pop, Flavia

    2015-01-01

    Summary Enantiopure (R,R) and (S,S)-dimethyl-bis(ethylenedithio)tetrathiafulvalene monosulfones have been synthesized by the aerial oxidation of the chiral dithiolates generated from the propionitrile-protected precursors. Both enantiomers crystallize in the orthorhombic chiral space group P212121. They show a boat-type conformation of the TTF moiety, a rather rigid dithiin sulfone ring and the methyl groups in a bisequatorial conformation. Cyclic voltammetry measurements indicate fully reversible oxidation in radical cation and dication species. PMID:26199666

  13. Synthesis of 3-O-sulfonated heparan sulfate octasaccharides that inhibit the herpes simplex virus type 1 host-cell interaction

    NASA Astrophysics Data System (ADS)

    Hu, Yu-Peng; Lin, Shu-Yi; Huang, Cheng-Yen; Zulueta, Medel Manuel L.; Liu, Jing-Yuan; Chang, Wen; Hung, Shang-Cheng

    2011-07-01

    Cell surface carbohydrates play significant roles in a number of biologically important processes. Heparan sulfate, for instance, is a ubiquitously distributed polysulfated polysaccharide that is involved, among other things, in the initial step of herpes simplex virus type 1 (HSV-1) infection. The virus interacts with cell-surface heparan sulfate to facilitate host-cell attachment and entry. 3-O-Sulfonated heparan sulfate has been found to function as an HSV-1 entry receptor. Achieving a complete understanding of these interactions requires the chemical synthesis of such oligosaccharides, but this remains challenging. Here, we present a convenient approach for the synthesis of two irregular 3-O-sulfonated heparan sulfate octasaccharides, making use of a key disaccharide intermediate to acquire different building blocks for the oligosaccharide chain assembly. Despite substantial structural differences, the prepared 3-O-sulfonated sugars blocked viral infection in a dosage-dependent manner with remarkable similarity to one another.

  14. Preparation and Characterization of Sulfonic Acid Functionalized Silica and Its Application for the Esterification of Ethanol and Maleic Acid

    NASA Astrophysics Data System (ADS)

    Sirsam, Rajkumar; Usmani, Ghayas

    2016-04-01

    The surface of commercially available silica gel, 60-200 mesh size, was modified with sulfonic acid through surface activation, grafting of 3-Mercaptopropyltrimethoxysilane, oxidation and acidification of 3-Mercaptopropylsilica. Sulfonic Acid Functionalization of Silica (SAFS) was confirmed by Fourier Transform Infra-red (FTIR) spectroscopy and thermal gravimetric analysis. Acid-base titration was used to estimate the cation exchange capacity of the SAFS. Catalytic activity of SAFS was judged for the esterification of ethanol with maleic acid. An effect of different process parameters viz. molar ratio, catalyst loading, speed of agitation and temperature were studied and optimized by Box Behnken Design (BBD) of Response Surface Methodology (RSM). Quadratic model developed by BBD-RSM reasonably satisfied an experimental and predicted values with correlation coefficient value R2 = 0.9504.

  15. Perfluorooctanoate and perfluorooctane sulfonate concentrations in surface water in Japan.

    PubMed

    Saito, Norimitsu; Harada, Kouji; Inoue, Kayoko; Sasaki, Kazuaki; Yoshinaga, Takeo; Koizumi, Akio

    2004-01-01

    Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are synthetic surfactants used in Japan. An epidemiological study of workers exposed to PFOA revealed a significant increase in prostate cancer mortality. A cross-sectional study of PFOA-exposed workers showed that PFOA perturbs sex hormone homeostasis. We analyzed their concentrations in surface water samples collected from all over Japan by LC/MS with a solid phase extraction method. The lowest limits of detection (LOD) (ng/L) were 0.06 for PFOA and 0.04 for PFOS. The lowest limits of quantification (LOQ) (ng/L) were 0.1 for both analytes. The levels [geometric mean (GM); geometric standard deviation (GS)] (ng/L) of PFOA and PFOS in the surface waters were GM (GS): 0.97 (3.06) and 1.19 (2.44) for Hokkaido-Tohoku (n=16); 2.84(3.56) and 3.69 (3.93) for Kanto (n=14); 2.50 (2.23) and 1.07 (2.36) for Chubu (n=17); 21.5 (2.28) and 5.73 (3.61) for Kinki (n=8); 1.51 (2.28) and 1.00 (3.42) for Chugoku (n=9); 1.93 (2.40) and 0.89 (3.09) for Kyushu-Shikoku (n=15). The GM of PFOA in Kinki was significantly higher than in other areas (ANOVA p<0.01). Systematic searches of Yodo and Kanzaki Rivers revealed two highly contaminated sites, a public-water-disposal site for PFOA and an airport for PFOS. The former was estimated to release 18 kg of PFOA/d. PFOA in drinking water in Osaka city [40 (1.07) ng/L] was significantly higher than in other areas. The present study confirms that recognizable amounts of PFOA are released in the Osaka area and that people are exposed to PFOA through drinking water ingestion. PMID:14960830

  16. Does perfluorooctane sulfonate (PFOS) act as chemosensitizer in zebrafish embryos?

    PubMed

    Keiter, Susanne; Burkhardt-Medicke, Kathleen; Wellner, Peggy; Kais, Britta; Färber, Harald; Skutlarek, Dirk; Engwall, Magnus; Braunbeck, Thomas; Keiter, Steffen H; Luckenbach, Till

    2016-04-01

    Earlier studies have shown that perfluorooctane sulfonate (PFOS) increases the toxicity of other chemicals by enhancing their uptake by cells and tissues. The present study aimed at testing whether the underlying mechanism of enhanced uptake of chemicals by zebrafish (Danio rerio) embryos in the presence of PFOS is by interference of this compound with the cellular efflux transporter Abcb4. Modifications of uptake/clearance and toxicity of two Abcb4 substrates, the fluorescent dye rhodamine B (RhB) and vinblastine, by PFOS were evaluated using 24 and 48h post-fertilization (hpf) embryos. Upon 90min exposure of 24hpf embryos to 1μM RhB and different PFOS concentrations (3-300μM) accumulation of RhB in zebrafish was increased by up to 11.9-fold compared to controls, whereas RhB increases in verapamil treatments were 1.7-fold. Co-administration of PFOS and vinblastine in exposures from 0 to 48hpf resulted in higher vinblastine-caused mortalities in zebrafish embryos indicating increased uptake of this compound. Interference of PFOS with zebrafish Abcb4 activity was further studied using recombinant protein obtained with the baculovirus expression system. PFOS lead to a concentration-dependent decrease of the verapamil-stimulated Abcb4 ATPase activity; at higher PFOS concentrations (250, 500μM), also the basal ATPase activity was lowered indicating PFOS to be an Abcb4 inhibitor. In exposures of 48hpf embryos to a very high RhB concentration (200μM), accumulation of RhB in embryo tissue and adsorption to the chorion were increased in the presence of 50 or 100μM PFOS. In conclusion, the results indicate that PFOS acts as inhibitor of zebrafish Abcb4; however, the exceptionally large PFOS-caused effect amplitude of RhB accumulation in the 1μM RhB experiments and the clear PFOS effects in the experiments with 200μM RhB suggest that an additional mechanism appears to be responsible for the potential of PFOS to enhance uptake of Abcb4 substrates. PMID:26803730

  17. Fabrication of protic ionic liquid/sulfonated polyimide composite membranes for non-humidified fuel cells

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Yul; Yasuda, Tomohiro; Watanabe, Masayoshi

    We have demonstrated that a protic ionic liquid, diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]) functions as a proton conductor and is suitable for use as an electrolyte in H 2/O 2 fuel cells, which can be operated at temperatures higher than 100 °C under non-humidified conditions. In this study, in order to fabricate a polymer electrolyte fuel cell, matrix polymers for [dema][TfO] are explored and sulfonated polyimides (SPI), in which the sulfonic acid groups are in diethylmethylammonium form, are found to be highly compatible with [dema][TfO]. Polymer electrolyte membranes for non-humidified fuel cells are prepared by the solvent casting method using SPI and [dema][TfO]. The SPI, with an ion exchange capacity of 2.27 meq g -1, can retain four times its own weight of [dema][TfO] and produces uniform, tough, and transparent composite membranes. The composite membranes have good thermal stability (>300 °C) and ionic conductivity (>10 -2 S cm -1 at 120 °C when the [dema][TfO] content is higher than 67 wt%) under anhydrous conditions. In the H 2/O 2 fuel cell operation using a composite membrane without humidification, a current density higher than 240 mA cm -2 is achieved with a maximum power density of 100 mW cm -2 at 80 °C.

  18. Preparation of sulfonic acid-containing rubbers from natural rubber vulcanizates

    NASA Astrophysics Data System (ADS)

    Poonsawat, Worapong; Poompradub, Sirilux; Ngamcharussrivichai, Chawalit

    2014-06-01

    In this work, a series of sulfonic acid-containing rubbers were prepared by aqueous phase oxidation of natural rubber vulcanizates in the presence of hydrogen peroxide (H2O2) and formic acid (HCOOH). The starting vulcanizates were neatly prepared via an efficient vulcanization (EV) system by varying mass ratio of N-cyclohexyl-2-benzothiazole sulfonamide (CBS), as an accelerator, to sulfur. The oxidation conditions were controlled at the molar ratio of H2O2: HCOOH = 1:1, the concentration of H2O2 = 15 wt.%, the temperature = 50 °C, and the reaction time = 3 h. The rubber materials before and after the oxidation were characterized for their physicochemical properties by using Fourier transform infrared spectroscopy, bomb calorimetry, acid-base titration and swelling measurements. The results indicated the presence of sulfonic acid group in the oxidized rubbers, generated by the oxidative cleaves of sulfide crosslinks in the rubber vulcanizates. The oxidation decreased the sulfur content of the rubber in which the level of sulfur loss was determined by the CBS/sulfur ratio. Moreover, the acidity of the oxidized products was correlated with the amount of sulfur remaining.

  19. Preparation and study of novel poly(sulfone-ester-amide)s

    SciTech Connect

    Bruma, M. , Mercer, F.; Gronewald, S.

    1995-12-31

    A series of novel poly(ester-amide)s containing sulfone groups in the main chain have been prepared and compared with related polymers which do not have sulfone bridges. Incorporation of sulfone moieties into the polymer backbone improved the solubility of these polymers without significant loss of their high thermal stability, and provided a large {open_quotes}window{close_quotes} between T{sub g} and decomposition temperature. Solutions of poly(sulfone-ester-amide)s in NMP have been cast into flexible films, having low dielectric constant. The synthesis and characterization of these new polymers will be presented.

  20. Sulfonates: A novel class of organic sulfur compounds in marine sediments

    NASA Astrophysics Data System (ADS)

    Vairavamurthy, Appathurai; Zhou, Weiqing; Eglinton, Timothy; Manowitz, Bernard

    1994-11-01

    X-ray absorption near-edge structure spectroscopy (XANES) used to measure sulfur speciation in a variety of organic-rich marine sediments has established sulfonates as a novel and major component of sedimentary organic sulfur. The origins of sulfonates in sediments are not clear, although both biological and geochemical mechanisms are possible. The accumulation of oxidized sulfonate sulfur in reducing marine sediments was not known previously; hence, a new perspective in sulfur geochemistry is established. The biogeochemical implications of the presence of sulfonates in marine sediments are discussed.

  1. Synthesis, characterization, antibacterial activity and quantum chemical studies of N'-Acetyl propane sulfonic acid hydrazide

    NASA Astrophysics Data System (ADS)

    Alyar, Saliha; Alyar, Hamit; Ozdemir, Ummuhan Ozmen; Sahin, Omer; Kaya, Kerem; Ozbek, Neslihan; Gunduzalp, Ayla Balaban

    2015-08-01

    A new N'-Acetyl propane sulfonic acid hydrazide, C3H7sbnd SO2sbnd NHsbnd NHsbnd COCH3 (Apsh, an sulfon amide compound) has been synthesized for the first time. The structure of Apsh was investigated using elemental analysis, spectral (IR, 1H/13C NMR) measurements. In addition, molecular structure of the Apsh was determined by single crystal X-ray diffraction technique and found that the compound crystallizes in monoclinic, space group P 21/c. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The structure of Apsh is optimized using Density Functional Theory (DFT) method. The vibrational band assignments were performed at B3LYP/6-311++G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology. The theoretical IR frequencies are found to be in good agreement with the experimental IR frequencies. Nonlinear optical (NLO) behaviour of Apsh is also examined by the theoretically predicted values of dipole moment (μ), polarizability (α0) and first hyperpolarizability (βtot). The antibacterial activities of synthesized compound were studied against Gram positive bacteria: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 23212, Staphylococcus epidermidis ATCC 34384, Gram negative bacteria: Eschericha coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70063 by using microdilution method (as MICs) and disc diffusion method.

  2. The Alkaline Hydrolysis of Sulfonate Esters: Challenges in Interpreting Experimental and Theoretical Data

    PubMed Central

    2013-01-01

    Sulfonate ester hydrolysis has been the subject of recent debate, with experimental evidence interpreted in terms of both stepwise and concerted mechanisms. In particular, a recent study of the alkaline hydrolysis of a series of benzene arylsulfonates (Babtie et al., Org. Biomol. Chem.10, 2012, 8095) presented a nonlinear Brønsted plot, which was explained in terms of a change from a stepwise mechanism involving a pentavalent intermediate for poorer leaving groups to a fully concerted mechanism for good leaving groups and supported by a theoretical study. In the present work, we have performed a detailed computational study of the hydrolysis of these compounds and find no computational evidence for a thermodynamically stable intermediate for any of these compounds. Additionally, we have extended the experimental data to include pyridine-3-yl benzene sulfonate and its N-oxide and N-methylpyridinium derivatives. Inclusion of these compounds converts the Brønsted plot to a moderately scattered but linear correlation and gives a very good Hammett correlation. These data suggest a concerted pathway for this reaction that proceeds via an early transition state with little bond cleavage to the leaving group, highlighting the care that needs to be taken with the interpretation of experimental and especially theoretical data. PMID:24279349

  3. Carbon nanotubes-blended poly(phenylene sulfone) membranes for ultrafiltration applications

    NASA Astrophysics Data System (ADS)

    Lawrence Arockiasamy, D.; Alam, Javed; Alhoshan, Mansour

    2013-03-01

    Multi-walled carbon nanotubes (MWCNT) were carboxylated by a chemical method. Poly(phenylene sulfone) (PPSU), MWCNT and functionalized (carboxylated) MWCNT/poly(phenylene sulfone) (PPSU) blend membranes were synthesized via the phase-inversion method. The resultant membranes were then characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle. The FMWCNT blend membranes appeared to be more hydrophilic, with higher pure water flux than did the pure PPSU and MWCNT/PPSU blend membranes. It was also found that the presence of multi-walled carbon nanotubes (MWCNTs) in the blend membranes was an important factor affecting the morphology and permeation properties of the membranes. The model proteins such as trypsin (20 kDa), pepsin (35 kDa), egg albumin (45 kDa) and bovine serum albumin (69 kDa) rejection experiments were carried out under identical operational conditions employing both PPSU and blend membranes. The membranes were also subjected to the determination of molecular weight cut-off (MWCO) using different molecular weights of proteins. During trypsin ultrafiltration, PPSU/MWCNT and PPSU/FMWCNT membranes showed a slower flux decline rate than did the PPSU membrane.

  4. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    DOE PAGESBeta

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformedmore » a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.« less

  5. Ionic liquids composed of phosphonium cations and organophosphate, carboxylate, and sulfonate as lubricant antiwear additives

    SciTech Connect

    Zhou, Yan; Dyck, Jeffrey; Graham, Todd; Luo, Huimin; Leonard, Donovan N.; Qu, Jun

    2014-10-20

    Oil-soluble phosphonium-based ionic liquids (ILs) have recently been reported as potential ashless lubricant additives. This study is to expand the IL chemistry envelope and to achieve fundamental correlations between the ion structures and ILs’ physiochemical and tribological properties. Here we present eight ILs containing two different phosphonium cations and seven different anions from three groups: organophosphate, carboxylate, and sulfonate. The oil solubility of ILs seems largely governed by the IL molecule size and structure complexity. When used as oil additives, the ranking of effectiveness in wear protection for the anions are: organophosphate > carboxylate > sulfonate. All selected ILs outperformed a commercial ashless anti-wear additive. Surface characterization from the top and the cross-section revealed the nanostructures and compositions of the tribo-films formed by the ILs. Some fundamental insights were achieved: branched and long alkyls improve the IL’s oil solubility, anions of a phosphonium-phosphate IL contribute most phosphorus in the tribofilm, and carboxylate anions, though free of P, S, N, or halogen, can promote the formation of an anti-wear tribofilm.

  6. Electroactive nanostructured polymer actuators fabricated using sulfonated styrenic pentablock copolymer/montmorillonite/ionic liquid nanocomposite membranes

    NASA Astrophysics Data System (ADS)

    Lee, Jang-Woo; Hong, Soon Man; Koo, Chong Min

    2014-08-01

    High-bendable, air-operable ionic polymer-metal composite (IPMC) actuators composed of electroactive nanostructured middle-block sulfonated styrenic pentablock copolymer (SSPB)/sulfonated montmorillonite (s-MMT) nanocomposite electrolyte membranes with bulky imidazolium ionic liquids (ILs) incorporated were fabricated and their bending actuation performances were evaluated. The SSPB-based IPMC actuators showed larger air-operable bending displacements, higher displacement rates, and higher energy efficiency of actuations without conventional IPMC bottlenecks, including back relaxation and actuation instability during actuation in air, than the Nafion counterpart. Incorporation of s-MMT into the SSPB matrix further enhanced the actuation performance of the IPMC actuators in terms of displacement, displacement rate, and energy efficiency. The remarkably high performance of the SSPB/s-MMT/IL IPMCs was considered to be due to the microphase-separated large ionic domains of the SSPB (the average diameter of the ionic domain: ca. 20 nm) and the role of s-MMT as an ionic bridge between the ionic domains, and the ion pumping effect of the bulky imidazolium cations of the ILs as well. The microphase-separated nanostructure of the composite membranes caused a high dimensional stability upon swelling in the presence of ILs, which effectively preserved the original electrode resistance against swelling, leading to a high actuation performance of IPMC.

  7. Modification of the cellulosic component of hemp fibers using sulfonic acid derivatives: Surface and thermal characterization.

    PubMed

    George, Michael; Mussone, Paolo G; Bressler, David C

    2015-12-10

    The aim of this study was to characterize the surface, morphological, and thermal properties of hemp fibers treated with two commercially available, inexpensive, and water soluble sulfonic acid derivatives. Specifically, the cellulosic component of the fibers were targeted, because cellulose is not easily removed during chemical treatment. These acids have the potential to selectively transform the surfaces of natural fibers for composite applications. The proposed method proceeds in the absence of conventional organic solvents and high reaction temperatures. Surface chemical composition and signature were measured using gravimetric analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red spectroscopy (FTIR). XPS data from the treated hemp fibers were characterized by measuring the reduction in O/C ratio and an increase in abundance of the C-C-O signature. FTIR confirmed the reaction with the emergence of peaks characteristic of disubstituted benzene and amino groups. Grafting of the sulfonic derivatives resulted in lower surface polarity. Thermogravimetric analysis revealed that treated fibers were characterized by lower percent degradation between 200 and 300 °C, and a higher initial degradation temperature. PMID:26428120

  8. Radiation and storage-induced ageing of polypyrrole doped with dodecylbenzene sulfonic acid

    NASA Astrophysics Data System (ADS)

    Kappen, P.; Brack, N.; Hale, P. S.; Prissanaroon, W.; Welter, E.; Pigram, P. J.

    2005-04-01

    The effects of storage and exposure to X-rays on the surface chemistry of electrochemically prepared polypyrrole (PPy) doped with dodecylbenzene sulfonic acid (DBSA) were investigated using X-ray photoelectron spectroscopy (XPS). For irradiation, different photon sources (lab source and synchrotron radiation) and energies (1.4-9 keV) were chosen. This covers an energy range of relevance for many X-ray based investigations (e.g. XPS or X-ray absorption spectroscopy) of PPy[DBSA], PPy-metal interfaces, and transition metals embedded into PPy. The DBSA doping level and the concentration ratio of sulfonate species are discussed as a function of storage and irradiation times, and links between both ageing parameters are given. New sulfur species are found to emerge upon repeated soft X-ray irradiation. Severe changes in the polaron/bipolaron structure of PPy[DBSA] during exposure to high energy (several keV) synchrotron radiation are observed, and the results are discussed in the light of photon absorption and photoelectron generation in the polymer surface.

  9. Molecular dynamics simulations of structural transformation of perfluorooctane sulfonate (PFOS) at water/rutile interfaces.

    PubMed

    He, Guangzhi; Zhang, Meiyi; Zhou, Qin; Pan, Gang

    2015-09-01

    Concentration and salinity conditions are the dominant environmental factors affecting the behavior of perfluorinated compounds (PFCs) on the surfaces of a variety of solid matrices (suspended particles, sediments, and natural minerals). However, the mechanism has not yet been examined at molecular scales. Here, the structural transformation of perfluorooctane sulfonate (PFOS) at water/rutile interfaces induced by changes of the concentration level of PFOS and salt condition was investigated using molecular dynamics (MD) simulations. At low and intermediate concentrations all PFOS molecules directly interacted with the rutile (110) surface mainly by the sulfonate headgroups through electrostatic attraction, yielding a typical monolayer structure. As the concentration of PFOS increased, the molecules aggregated in a complex multi-layered structure, where an irregular assembling configuration was adsorbed on the monolayer structure by the van der Waals interactions between the perfluoroalkyl chains. When adding CaCl2 to the system, the multi-layered structure changed to a monolayer again, indicating that the addition of CaCl2 enhanced the critical concentration value to yield PFOS multilayer assemblies. The divalent Ca(2+) substituted for monovalent K(+) as the bridging counterion in PFOS adsorption. MD simulation may trigger wide applications in study of perfluorinated compounds (PFCs) from atomic/molecular scale. PMID:25966457

  10. Determination of methiocarb and its degradation products, methiocarb sulfoxide and methiocarb sulfone, in bananas using QuEChERS extraction.

    PubMed

    Plácido, Alexandra; Paíga, Paula; Lopes, David H; Correia, Manuela; Delerue-Matos, Cristina

    2013-01-16

    The present work describes the development of an analytical method for the determination of methiocarb and its degradation products (methiocarb sulfoxide and methiocarb sulfone) in banana samples, using the QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure followed by liquid chromatography coupled to photodiode array detector (LC-PAD). Calibration curves were linear in the range of 0.5-10 mg L⁻¹ for all compounds studied. The average recoveries, measured at 0.1 mg kg⁻¹ wet weight, were 92.0 (RSD = 1.8%, n = 3), 84.0 (RSD = 3.9%, n = 3), and 95.2% (RSD = 1.9%, n = 3) for methiocarb sulfoxide, methiocarb sulfone, and methiocarb, respectively. Banana samples treated with methiocarb were collected from an experimental field. The developed method was applied to the analysis of 24 samples (peel and pulp) and to 5 banana pulp samples. Generally, the highest levels were found for methiocarb sulfoxide and methiocarb. Methiocarb sulfone levels were below the limit of quantification, except in one sample (not detected). PMID:23252625

  11. Interactions of formate ion with triplets of anthraquinone-2-sulfonate, 1,4-naphthoquinone, benzophenone-4-carboxylate, and benzophenone-4-sulfonate

    SciTech Connect

    Loeff, I.; Goldstein, S.; Treinin, A. ); Linschitz, H. )

    1991-05-30

    The interaction of formate with the triplet states of naphthoquinone (NQ), anthraquinone-2-sulfonate (AQS), benzophenone-4-carboxylate (BC), and benzophenone-4-sulfonate (BS) was studied by laser flash photolysis. Rate constants were determined either by direct measurement of triplet lifetimes or by inhibition of product yields by competitive reactants. Radical products are formed in two stages, direct reduction by formate and efficient secondary reduction by initially formed CO{sub 2}{sup {sm bullet}{minus}} radicals. The quinones react by electron transfer with quenching rate constants k{sub q}(NQ) = 3 {times} 10{sup 9} and k{sub q}(AQS) = 4 {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}, giving anion radicals with primary yields of {phi}{sub R}(NQ) {approximately} 0.7 and {phi}{sub R}(AQS) {approximately} 0.3. Formic acid quenches {sup 3}AQS much more slowly. The less strongly oxidizing ketone triplets react by H-atom abstraction, k{sub q}(BC) = 1.3 {times} 10{sup 7} and k{sub q}(BS) = 5.3 {times} 10{sup 7} M{sup {minus}1} s{sup {minus}1}, giving protonated ketyl radicals with primary yields {phi}{sub R} {approximately} 0.7. Photoreduction of BC exhibits a deuterium isotope effect, k{sub H}/k{sub D} = 1.6, whereas AQS shows none. A new, short-lived transient, E, is observed in the {sup 3}AQS-formate reaction, which may be an exciplex or adduct. The redox potential, E{degree}{prime}(NQ/NQ{sup {sm bullet}{minus}}) = {minus}0.12 V, and rate constants for radical reactions of NQ and O{sub 2} were measured by pulse radiolysis. The results are discussed in terms of pertinent redox potentials, bond strengths, and the nature of the exciplex intermediates.

  12. Leaching and primary biodegradation of sulfonated naphthalenes and their formaldehyde condensates from concrete superplasticizers in groundwater affected by tunnel construction.

    PubMed

    Ruckstuhl, Sabine; Suter, Marc J F; Kohler, Hans-Peter E; Giger, Walter

    2002-08-01

    Sulfonated naphthalenes and their formaldehyde condensates (SNFC) are used as concrete superplasticizers fortunnel construction through aquifers.This paperdiscusses their primary biodegradation in groundwater affected by construction activities. The analyses of groundwater samples collected 5 m away from a construction site clearly indicated that components of the applied SNFC product leached into the groundwater. A maximum total concentration of these compounds of 233 microg/L was found, and it was shown that only the monomeric sulfonated naphthalenes andthe condensates uptothetetramerleached in substantial amounts. The decrease in concentration of several monomeric components could not be explained by mere dispersion but rather indicates a biological transformation in the aquifer. This was confirmed at a second field site and by laboratory degradation experiments with piezometer material as inoculum. Lag phases for the individually degradable sulfonated naphthalenes ranged from 0 to 96 d. Naphthalene-1,5-disulfonate and the oligomeric components were neither degraded in the aquifer nor in the laboratory experiments within an observation time of up to 195 d. This clearly indicates their persistence in subsurface waters. PMID:12188355

  13. Functionalized carbon nanotube-poly(arylene sulfone) composite membranes for direct methanol fuel cells with enhanced performance

    NASA Astrophysics Data System (ADS)

    Joo, Sang Hoon; Pak, Chanho; Kim, Eun Ah; Lee, Yoon Hoi; Chang, Hyuk; Seung, Doyoung; Choi, Yeong Suk; Park, Jong-Bong; Kim, Tae Kyoung

    A new type of composite membrane, consisting of functionalized carbon nanotubes (CNTs) and sulfonated poly(arylene sulfone) (sPAS), is prepared for direct methanol fuel cell (DMFC) applications. The CNTs modified with sulfonic acid or PtRu nanopaticles are dispersed within the sPAS matrix by a solution casting method to afford SO 3CNT-sPAS or PtRu/CNT-sPAS composite membranes, respectively. Characterization of the composite membranes reveals that the functionalized CNTs are homogeneously distributed within the sPAS matrix and the composite membranes contain smaller ion clusters than the neat sPAS. The composite membranes exhibit enhanced mechanical properties in terms of tensile strength, strain and toughness, which leads to improvements in ion conductivity and methanol permeability compared with the neat sPAS membrane. In DMFC performance tests, the use of a PtRu/CNT-sPAS membrane yields high power density compared with the neat sPAS membrane, which demonstrates that the improved properties of the composite membranes induce an increase in power density. The strategy for CNT-sPAS composite membranes presented in this work can potentially be extended to other CNT-polymer composite systems.

  14. Hydrogen bond cross-linked sulfonated poly(imino ether ether ketone) (PIEEK) for fuel cell membranes

    NASA Astrophysics Data System (ADS)

    Chang, Guanjun; Shang, Zhenfang; Yang, Li

    2015-05-01

    A new diamine monomer, 3,3‧-dihydroxydiphenylamine, is prepared by the palladium catalyzed C-N coupling reaction and the following reduction reaction of 3-bromoanisole and m-anisidine. A series of novel hydrogen bond cross-linked sulfonated poly(imino ether ether ketone) (SPIEEK) are obtained by the copolymerization of sodium 5,5‧-carbonylbis(2-fluorobenzene sulfonate), 4,4‧-difluorobenzophenone with 3,3‧-dihydroxydiphenylamine. The structures of resulting polymers are characterized by means of FT-IR, 1H NMR spectroscopy, and elemental analysis; the results show an agreement with the proposed structure. The resulting SPIEEK membranes display much better resistance to swelling than these without imino groups due to the strong interchain interaction through imino and sulfonic acid groups. The SPIEEK-60 and SPIEEK-80 membrane show the proton conductivity of 0.118 and 0.154 S cm-1 at 80 °C which is higher than Nafion 117 (0.082 S cm-1 at 80 °C). Moreover, the SPIEEK membranes exhibit good mechanical properties and lower methanol permeability due to the hydrogen bondings between the polymer chains.

  15. Methylation, Glucuronidation, and Sulfonation of Daphnetin in Human Hepatic Preparations In Vitro: Metabolic Profiling, Pathway Comparison, and Bioactivity Analysis.

    PubMed

    Liang, Si-Cheng; Xia, Yang-Liu; Hou, Jie; Ge, Guang-Bo; Zhang, Jiang-Wei; He, Yu-Qi; Wang, Jia-Yue; Qi, Xiao-Yi; Yang, Ling

    2016-02-01

    Our previous study demonstrated that daphnetin is subject to glucuronidation in vitro. However, daphnetin metabolism is still poorly documented. This study aimed to investigate daphnetin metabolism and its consequent effect on the bioactivity. Metabolic profiles obtained by human liver S9 fractions and human hepatocytes showed that daphnetin was metabolized by glucuronidation, sulfonation, and methylation to form 6 conjugates which were synthesized and identified as 7-O-glucuronide, 8-O-glucuronide, 7-O-sulfate and 8-O-sulfate, 8-O-methylate, and 7-O-suflo-8-O-methylate. Regioselective 8-O-methylation of daphnetin was investigated using in silico docking calculations, and the results suggested that a close proximity (2.03 Å) of 8-OH to the critical residue Lysine 144 might be the responsible mechanism. Compared with glucuronidation and sulfonation pathways, the methylation of daphnetin had a high clearance rate (470 μL/min/mg) in human liver S9 fractions and contributed to a large amount (37.3%) of the methyl-derived metabolites in human hepatocyte. Reaction phenotyping studies showed the major role of SULT1A1, -1A2, and -1A3 in daphnetin sulfonation, and soluble COMT in daphnetin 8-O-methylation. Of the metabolites, only 8-O-methyldaphnetin exhibited an inhibitory activity on lymphocyte proliferation comparable to that of daphnetin. In conclusion, methylation is a crucial pathway for daphnetin clearance and might be involved in pharmacologic actions of daphnetin in humans. PMID:26869431

  16. Effects of repeated wet/dry cycling on the structure and performance of sulfonated pentablock copolymer membranes

    NASA Astrophysics Data System (ADS)

    Truong, Phuc; Stein, Gila

    Sulfonated block copolymers have shown potential as membranes for water purification. However, the performance of these materials under cyclic wet/dry conditions is not well understood. We measured the membrane structure, mechanical properties, and water vapor transport rates in a sulfonated pentablock copolymer as a function of the number of wet/dry cycles. The polymer is synthesized with an ABCBA block sequence, where A is poly(t-butyl styrene), B is poly(hydrogenated isoprene), and C is poly(styrene sulfonate). The ion exchange capacity is 2 meq, and membranes were prepared by coating from a solution. Using small angle X-ray scattering, we find the structure in as-prepared membranes resembles disordered micelles, and the characteristic length scale swells slightly with each wet/dry cycle. This lattice swelling is likely constrained by the glassy end-blocks. We also detect a lower yield point and less overall tensile strength with repeated cycling. Water vapor transport rates vary with the number of wet/dry cycle, however no specific trend was observed.

  17. Ionic polymer metal composite actuators employing irradiation-crosslinked sulfonated poly(styrene-ran-ethylene) as ion-exchange membranes

    NASA Astrophysics Data System (ADS)

    Wang, Xuanlun; Cheng, Tai-Hong; Xu, Liang; Oh, Il-Kwon

    2009-07-01

    Ionic polymer metal composites (IPMC) are soft polymeric smart materials having large displacement at low voltage in moist environments or water. This type of actuators consists of an ionic membrane and noble metal electrodes plated on both surfaces. The ion-exchange membrane, Nafion, remains as the benchmark for a majority of research and development in IPMC technology. In this research, we employed sulfonated poly(styrene-ran-ethylene) (SPSE) that is crosslinked by UV irradiation as a novel ionic membrane. The crosslinking reaction between polymer matrix and crosslinking agent was proved by FTIR analysis. The sulfonic acid groups were stable during the UV irradiation crosslinking process. Water uptake, ion exchange capacity, and sulfonation degree are characterized for both pure SPSE and crosslinked SPSE membrane. The bending responses of SPSE actuators under both direct current (DC) and alternating current (AC) excitations were investigated. The voltage-current behaviors of the actuators under AC excitations are also measured. Results showed the crosslinked SPSE actuators have better electromechanical performance than that of pure SPSE actuator with regard to tip displacement.

  18. Polyether sulfone/hydroxyapatite mixed matrix membranes for protein purification

    NASA Astrophysics Data System (ADS)

    Sun, Junfen; Wu, Lishun

    2014-07-01

    This work proposes a novel approach for protein purification from solution using mixed matrix membranes (MMMs) comprising of hydroxyapatite (HAP) inside polyether sulfone (PES) matrix. The influence of HAP particle loading on membrane morphology is studied. The MMMs are further characterized concerning permeability and adsorption capacity. The MMMs show purification of protein via both diffusion as well as adsorption, and show the potential of using MMMs for improvements in protein purification techniques. The bovine serum albumin (BSA) was used as a model protein. The properties and structures of MMMs prepared by immersion phase separation process were characterized by pure water flux, BSA adsorption and scanning electron microscopy (SEM).

  19. Sulfone/Ester Polymers Containing Pendent Ethynyl Groups

    NASA Technical Reports Server (NTRS)

    Hergenrother, P. M.; Jensen, B. J.

    1986-01-01

    Two processes make high-performance polymers resistant to solvents, without compromising mechanical characteristics. Polymers show improved solvent resistance while retaining high toughness, thermoformability, and mechanical performance. Multistep process involves conversion of pendent bromo group to ethynyl group, while direct process involves reacting hydroxy-terminated sulfone oligomers or polymers with stoichiometric amount of 5-(4-ethynylphenoxy) isophthaloyl chloride. Applications for new polymers include adhesives, composite resin matrices, moldings, ultrafiltration membranes, protective coatings, and such electrical insulators as thin films for microelectronic circuitry.

  20. The Palladium-Catalyzed Trifluoromethylation of Vinyl Sulfonates

    PubMed Central

    Cho, Eun Jin; Buchwald, Stephen L.

    2011-01-01

    A method for the palladium-catalyzed trifluoromethylation of cyclohexenyl sulfonates has been developed. Various cyclohexenyl triflates and nonaflates underwent trifluoromethylation under mild reaction conditions using a catalyst system composed of Pd(dba)2 or [(allyl)PdCl]2 and the monodentate biaryl phosphine ligand tBuXPhos. The trifluoromethyl anion (CF3−) or its equivalent for the process was generated in situ from TMSCF3 in combination with KF or TESCF3 in combintion with RbF. PMID:22111687

  1. Ammonium 4-meth-oxy-benzene-sulfonate.

    PubMed

    Suarez, Sebastián; Doctorovich, Fabio; Baggio, Ricardo

    2012-07-01

    The mol-ecular structure of the title compound, NH(4) (+)·C(7)H(7)O(4)S(-), is featureless [the methoxy C atom deviating 0.173 (6) Å from the phenyl mean plane] with inter-atomic distances and angles in the expected ranges. The main feature of inter-est is the packing mode. Hydro-philic (SO(3) and NH(4)) and hydro-phobic (PhOCH(3)) parts in the structure segregate, the former inter-acting through a dense hydrogen-bonding scheme, leading to a well connected two-dimensional structure parallel to (100) and the latter hydro-phobic groups acting as spacers for an inter-planar separation of c/2 = 10.205 (2) Å. In spite of being aligned along [110], the benzene rings stack in a far from parallel fashion [viz. consecutive ring centers determine a broken line with a 164.72 (12)° zigzag angle], thus preventing any possible π-π inter-action. PMID:22798885

  2. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and alkylated sulfonated diphenyl oxide, amine salt (PMN P-93-353) are subject to reporting under this section for the...) Release to water. Requirements as specified in § 721.90 (a)(4), (b)(4), and (c)(4) (where N = 20 ppb)....

  3. Bis-sulfonic acid ionic liquids for the conversion of fructose to 5-hydroxymethyl-2-furfural.

    PubMed

    Sim, Sang Eun; Kwon, Sunjeong; Koo, Sangho

    2012-01-01

    Homogenous bis-sulfonic acid ionic liquids (1 mol equiv.) in DMSO (10 mol equiv.) at 100 °C efficiently mediated the conversion of D-fructose into 5-hydroxymethyl-2-furfural in 75% isolated yield, which was roughly a 10% increment compared to the case of the mono-sulfonic acid ionic liquids. PMID:23114616

  4. Solvation Behavior of Short-chain Polystyrene Sulfonate in Aqueous Electrolyte Solutions: A Molecular Dyamics Study

    SciTech Connect

    Chialvo, Ariel A; Simonson, J Michael {Mike}

    2005-01-01

    We analyze the solvation behavior of short-chain polystyrene sulfonate (PSS) in aqueous electrolyte solutions by isothernal-isochoric molecular dynamics simulation to determine the solvation effects on the structure and conformation of the polyelectrolyte as a function of the aqueous environment. To that end, we study these aqueous systems including the explicit atomistic description of water, the PSS chain, and their interactions with all species in solution. In addition, we investigate the effect of the degree of sulfonation and its distribution along the PSS chain on the resulting conformation as well as solvation structure. Moreover, we assess the impact of added salts on the net charge of the PSS backbone, placing emphasis on the valence of the counterion and the extent of the ion-pair formation between the sulfonate group and the counterions. Finally, we present evidence for the so-called like-charge attraction between sulfonate groups through the formation of counterion-mediated interchain sulfonate-sulfonate and water-mediated intrachain sulfonate-sulfonate bridges, as well as between unlike counterion-counterion interactions.

  5. 40 CFR 721.10487 - Alkylbenzenes sulfonic acids, metal salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... salts (generic). 721.10487 Section 721.10487 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10487 Alkylbenzenes sulfonic acids, metal salts (generic). (a) Chemical... as alkylbenzenes sulfonic acids, metal salts (PMNs P-04-599, P-04-600, P-04-605, and P-04-606)...

  6. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737)...

  7. Synthesis and Structure-Property Relationships of Poly(sulfone)s for Anion Exchange Membranes

    SciTech Connect

    Yan, JL; Moore, HD; Hibbs, MR; Hickner, MA

    2013-10-05

    Membranes based on cationic polymers that conduct anions are important for enabling alkaline membrane fuel cells and other solid-state electrochemical devices that operate at high pH. Anion exchange membranes with poly(arylene ether sulfone) backbones are demonstrated by two routes: chloromethylation of commercially available poly(sulfone)s or radical bromination of benzylmethyl moieties in poly(sulfone)s containing tetramethylbisphenol A monomer residues. Polymers with tethered trimethylbenzyl ammonium moieties resulted from conversion of the halomethyl groups by quaternization with trimethyl amine. The water uptake of the chloromethylated polymers was dependent on the type of poly(sulfone) backbone for a given IEC. Bisphenol A-based Udel (R) poly(sulfone) membranes swelled in water to a large extent while membranes from biphenol-based Radel (R) poly(sulfone), a stiffer backbone than Udel, only showed moderate water uptake. The water uptake of cationic poly(sulfone)s was further reduced by synthesizing tetramethylbisphenol A and 4,4-biphenol-containing poly(sulfone) copolymers where the ionic groups were clustered on the tetramethylbisphenol A residues. The conductivity of all samples scaled with the bulk water uptake. The hydration number of the membranes could be increased by casting membranes from the ionic form polymers versus converting the halomethyl form cast polymers to ionic form in the solid state. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1790-1798, 2013

  8. Aryl sulfonates as neutral photoacid generators (PAGs) for EUV lithography

    NASA Astrophysics Data System (ADS)

    Sulc, Robert; Blackwell, James M.; Younkin, Todd R.; Putna, E. Steve; Esswein, Katherine; DiPasquale, Antonio G.; Callahan, Ryan; Tsubaki, Hideaki; Tsuchihashi, Tooru

    2009-03-01

    EUV lithography (EUVL) is a leading candidate for printing sub-32 nm hp patterns. In order for EUVL to be commercially viable at these dimensions, a continuous evolution of the photoresist material set is required to simultaneously meet the aggressive specifications for resolution, resist sensitivity, LWR, and outgassing rate. Alternative PAG designs, especially if tailored for EUVL, may aid in the formation of a material set that helps achieve these aggressive targets. We describe the preparation, characterization, and lithographic evaluation of aryl sulfonates as non-ionic or neutral photoacid generators (PAGs) for EUVL. Full lithographic characterization is reported for our first generation resist formulation using compound H, MAP-1H-2.5. It is benchmarked against MAP-1P-5.0, which contains the well-known sulfonium PAG, triphenylsulfonium triflate (compound P). Z-factor analysis indicates nZ32 = 81.4 and 16.8 respectively, indicating that our first generation aryl sulfonate formulations require about 4.8x improvement to match the results achieved with a model onium PAG. Improving the acid generation efficiency and use of the generated byproducts is key to the continued optimization of this class of PAGs. To that end, we believe EI-MS fragmentation patterns and molecular simulations can be used to understand and optimize the nature and efficiency of electron-induced PAG fragmentation.

  9. Sulfonated Poly(styrene) Chains Grafted on Magnetic Nanoparticles

    NASA Astrophysics Data System (ADS)

    Jiao, Yang; Yevelev, Anton; Parra, Javier; Akcora, Pinar; Stevens Institute of Technology Team

    2014-03-01

    Iron oxide nanoparticles functionalized with poly(styrene) (PS) chains at various grafting densities and loadings present stable and ordered nanostructures for tuning the mechanical and conductive properties in polymer composites. Strings, spherical and anisotropic clusters and well-dispersed particles are achieved with PS-grafted Fe3O4 nanoparticles in PS matrices upon varying the system parameters. In this work, we report the effect of sulfonic group locations on the aggregation state of polymer-grafted nanoparticles. Structures formed by the random and diblock copolymers of PS-poly(styrene sulfonate) (PSS) grafted particles will be discussed with small-angle x-ray scattering (SAXS) measurements in solution and melts. The conformational changes in PS-grafted chains and ion-containing grafts will be also presented in small-angle neutron-scattering (SANS) results to understand the role of polymer on the assembly of particles at the low grafting density. We acknowledge support by NSF-CAREER-DMR (#1048865).

  10. Membrane ultrafiltration of sulfonates and oil from micellar flooding wastewaters. Final report

    SciTech Connect

    Dubey, S.; Perez, N.L.; Ramakrishnan, B.; Thompson, R.E.

    1981-09-01

    Two membrane ultrafilters were tested with simulated micellar-flood wastewaters. The waters were brine containing oil, sulfonate, butyl alcohol, and polymer. Two sulfonates, one essentially oil-soluble and one essentially water-soluble, were used. The polymer used was polyacrylamide, except for a few runs done with xanthan gum. The membranes produced permeates containing very little oil, sulfonate or polymer. The butyl alcohol apparently passed through quantitatively. The cellulosic membrane tested was more effective than the polymeric membrane in that it gave better flux rates and was easier to clean when fouled. A field sample was run with the cellulosic membrane. The field sample contained crude-oil sulfonate which, unlike the commercial surfactants used in the simulated wastewaters, passed through the membrane almost quantitatively. Membrane ultrafiltration will not be of use in purifying water containing such sulfonates.

  11. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  12. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  13. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  14. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  15. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic...

  16. A new strategy for the synthesis of taurine derivatives using the 'safety-catch' principle for the protection of sulfonic acids.

    PubMed

    Seeberger, Sonja; Griffin, Roger J; Hardcastle, Ian R; Golding, Bernard T

    2007-01-01

    The safety-catch principle has been applied for the development of a new method for protecting sulfonic acids. 2,2-Dimethylsuccinic acid was reduced to 2,2-dimethylbutane-1,4-diol, which was selectively silylated to give 4-(tert-butyldiphenylsilanyloxy)-2,2-dimethylbutan-1-ol. Reaction of the latter compound with 2-chloroethanesulfonyl chloride in the presence of triethylamine afforded 4-(tert-butyldiphenylsilyloxy)-2,2-dimethylbutyl ethenesulfonate directly. The ethenesulfonate underwent Michael-type addition with secondary amines to give protected derivatives of taurine (2-aminoethanesulfonic acid). Deprotection was achieved on treatment with tetrabutylammonium fluoride, whereby cleavage of the silicon-oxygen bond led to an intermediate alkoxide that immediately cyclised to 2,2-dimethyltetrahydrofuran with liberation of a sulfonate. Pure sulfonic acids were obtained from the crude product by ion exchange chromatography on a strongly basic resin, which was eluted with aqueous acetic acid. The method developed should be generally applicable to the protection of sulfonic acids and is amenable to a multiparallel format. PMID:17164917

  17. Effect of the incorporation of sulfonated chitosan/sulfonated graphene oxide on the proton conductivity of chitosan membranes

    NASA Astrophysics Data System (ADS)

    Shirdast, Abbas; Sharif, Alireza; Abdollahi, Mahdi

    2016-02-01

    Chitosan biopolymer (CS) has been attracting considerable interest as polymer electrolyte in fuel cells. However, proton conductivity of chitosan is low and it is necessary to enhance its conductivity. In this work, 10 wt% sulfonated chitosan (SCS) and different amounts of sulfonated graphene oxide (SGO) nanosheets are incorporated into a chitosan membrane to investigate their effects on the electrochemical properties of the membrane. The proton conductivity and methanol permeability tests conducted on the CS/SCS/SGO membranes show that the conductivity is increased by 454%, the permeability is reduced by 23% and hence the selectivity is increased by 650%, relative to the neat chitosan, at SGO content of 5 wt%. Furthermore, combined addition of SCS and SGO to chitosan causes much more proton conductivity enhancement than the individual additives due to the synergistic effect of SCS and SGO. The observed synergistic effect reveals the importance of the chemical functionality of chitosan and nanofillers in the formation of ionic cluster domains with enhanced size within the membranes for proton transport. Finally, a Nernst-Planck based model is applied to the experimental proton conductivity data in order to shed more light on the role of GOs in the proton conductivity mechanism of chitosan.

  18. Sulfonated polyphosphazene-based membranes for use in direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Carter, Roy Lee

    Novel crosslinked and sulfonated poly[bis(3-methylphenoxy)phosphazene] blended proton exchange membranes were fabricated for use as the solid polymer electrolyte in a direct methanol fuel cell. Three polymers, polybenzimidazole, polyacrylonitrile and polyvinylidene fluoride-co-polyhexafluoropropylene were found to be compatible for blending with sulfonated polyphosphazene. A combination of blending and crosslinking was shown to be an effective method of producing durable, low water swelling films with acceptable proton conductivity. A novel tracer-diffusion 1H NMR method was developed and used to measure the mutual diffusion of methanol in non-crosslinked and crosslinked membranes composed of sulfonated polyphosphazene. The technique measures the growth of a solute NMR signal in the bulk (external) solution as it diffuses out of a thin film membrane. The transient increase in methanol peak height during analyte (methanol) desorption was fitted to a simple theoretical diffusion model using the methanol diffusion coefficient as an adjustable parameter. This method was found to be fast, reproducible, and accurate to within about +/-20%. Diffusion coefficients at 25°C were in the range of 1.0 x 10-8 cm2/s to 4.0 x 10-7 cm2/s for methanol concentrations of 1.0--5.0 M and were significantly smaller than those reported for a NafionRTM perfluorosulfonic acid membrane. Direct liquid methanol fuel cell tests were performed with membrane electrode assemblies (MEAs) fabricated with polyphosphazene-based proton-exchange membranes. MEAs worked best when high ion-exchange capacity (high conductivity) polyphosphazene membrane contacted the electrodes, in which case the fuel cell power output was nearly the same as that with Nafion 117 (for current densities ≤0.15 A/cm2), but the methanol crossover was three times lower than that of Nafion. The electrochemical performance of single-membrane MEAs with low conductivity S-POP/PAN films was poor, although the methanol crossover was

  19. Sulfonation of 17β-estradiol and inhibition of sulfotransferase activity by polychlorobiphenylols and celecoxib in Channel catfish, Ictalurus punctatus

    PubMed Central

    Wang, Li-Quan; James, Margaret O.

    2007-01-01

    The sulfonation of 17β-estradiol (E2) by human liver and recombinant sulfotransferases is influenced by environmental contaminants such as hydroxylated metabolites of polychlorinated biphenyls (OH-PCBs), which are potent inhibitors, and the therapeutic drug, celecoxib, which affects positional sulfonation of E2. In some locations, the aquatic environment is contaminated by PCBs, OH-PCBs and widely used therapeutic drugs. The objectives of this study were to investigate the sulfonation kinetics of E2 in liver cytosol from channel catfish (Ictalurus punctatus); to examine the effect of OH-PCBs on E2 sulfonation; and to determine if celecoxib altered the position of E2 sulfonation, as it does with human liver cytosol. E2 was converted to both 3- and 17-sulfates by catfish liver cytosol. At E2 concentrations below 1 μM, formation of E2-3-sulfate (E2-3-S) predominated, but substrate inhibition was observed at higher concentrations. Rates of E2-3-S formation at different E2 concentrations were fit to a substrate inhibition model, with K′m and V′max values of 0.40 ± 0.10 μM and 91.0 ± 4.7 pmol/min/mg protein, respectively and Ki of 1.08 ± 0.09 μM. The formation of E2-17-S fit Michaelis-Menten kinetics over the concentration range 25 nM to 2.5 μM, with Km and Vmax values of 1.07 ± 0.23 μM and 25.7 ± 4.43 pmol/min/mg protein, respectively. The efficiency (Vmax/Km) of formation of E2-3-S was 9.8-fold higher than that of E2-17-S. Several OH-PCBs inhibited E2 3-sulfonation, measured at an E2 concentration of 1 nM. Of those tested, the most potent inhibitor was 4′-OH-CB79, with two chlorine atoms flanking the OH group (IC50: 94 nM). The inhibition of estrogen sulfonation by OH-PCBs may disrupt the endocrine system and thus contribute to the known toxic effects of these compounds. Celecoxib did not stimulate E2-17-S formation, as is the case with human liver cytosol, but did inhibit the formation of E2-3-S (IC50: 44 μM) and to a lesser extent, E2-17-S (IC50

  20. Effect of linear alkyl benzene sulfonate on germination of spores of the aquatic fern Ceratopteris thalictroides

    SciTech Connect

    Singh, J.; Devi, S. )

    1989-07-01

    Validity of fern spore germination bioassays for the effects of environmental pollution was established by many researchers. Some workers studied the phytotoxicity of linear alkyl benzene sulfonate (LAS) on the spores of Diplazium esculentum and observed that LAS levels above 0.001% are toxic to fern spores. Water pollution due to synthetic detergents has been increasing continuously during the last few years due to their extensive use in domestic life, agriculture and industry. These detergents are among the most common pollutants responsible for water pollution. In view of this fact, the phytotoxicity of LAS on germination of an aquatic fern Ceratopteris thalictroides spores was studied. However, in these studies, only germination pattern was taken as index and no observations were made on the developmental stages.

  1. Evaluation of linear dodecyl benzene sulfonic acid as a teat dip in a commercial dairy.

    PubMed

    Pankey, J W; Boddie, R L; Philpot, W N

    1984-06-01

    A postmilking teat dip containing 1.94% linear dodecyl benzene sulfonic acid was evaluated for approximately 6 mo on a commercial dairy farm that milked an average of 75 cows. Sixteen Staphylococcus aureus infections were diagnosed, 12 in the undipped control quarters and 4 in the dipped. Incidence of intramammary infection with Staphylococcus aureus was reduced 68.1%. Seventy-five infections were diagnosed as micrococci, 42 in control and 33 in the dipped group, a 23.6% reduction. A total of 37 Corynebacterium sp. infections were diagnosed, 21 and 16 in control and dipped groups, a 25.8% reduction. Teat skin condition did not change during the study. PMID:6747046

  2. High electrokinetic energy conversion efficiency in charged nanoporous nitrocellulose/sulfonated polystyrene membranes.

    PubMed

    Haldrup, Sofie; Catalano, Jacopo; Hansen, Michael Ryan; Wagner, Manfred; Jensen, Grethe Vestergaard; Pedersen, Jan Skov; Bentien, Anders

    2015-02-11

    The synthesis, characterization, and electrokinetic energy conversion performance have been investigated experimentally in a charged polymeric membrane based on a blend of nitrocellulose and sulfonated polystyrene. The membrane is characterized by a moderate ion exchange capacity and a relatively porous structure with average pore diameter of 11 nm. With electrokinetic energy conversion, pressure can be converted directly into electric energy and vice versa. From the electrokinetic transport properties, a remarkably large intrinsic maximum efficiency of 46% is found. It is anticipated that the results are an experimental verification of theoretical models that predict high electrokinetic energy conversion efficiency in pores with high permselectivity and hydrodynamic slip flow. Furthermore, the result is a promising step for obtaining efficient low-cost electrokinetic generators and pumps for small or microscale applications. PMID:25555128

  3. Nanostructure and Properties of Sulfonated Polyarylenethioethersulfone Copolymers as Proton Exchange Fuel Cell Membranes

    SciTech Connect

    Yoonessi,M.; Bai, Z.; Dang, T.

    2007-01-01

    A systematic investigation of properties and nanostructure of sulfonated polyarylenethioethersulfone (SPTES) copolymer proton exchange membranes for fuel cell applications has been presented. SPTES copolymers are high temperature resistant (250 C), and form tough films with excellent proton conductivity up to 170 {+-} 5 mS/cm (SPTES 70 @ 85 C, 85%RH). Small angle X-ray scattering of hydrated SPTES 70 revealed the presence of local water domains (diameter {approx}5 nm) within the copolymer. The high proton conductivity of the membranes is attributed to the formation of these ionic aggregates containing water molecules, which facilitate proton transfer. AFM studies of SPTES 70 as a function of humidity (25-65%RH) showed an increase in hydrophilic domains with increasing humidity at 22 C.

  4. Synthesis and photopolymerization kinetics of a novel oxime ester sulfonic acid photoacid generator

    NASA Astrophysics Data System (ADS)

    Pang, Yu-Lian; Zou, Ying-Quan

    2012-03-01

    On the basis of the chemical structure of (5-Hydroxyimino-5H-thiophen-2-ylidene)-phenylacetonitrile, we synthesized a novel sulfonic oxime ester photoacid generator named (5-Ptoluenesulfonyloxyimino- 5H-thiophen-2-ylidene)-phenyl-acetonitrile (TTPA),which was an efficient Photoacid generator (PAG) for 405nm violet laser imaging system.It was synthesized from 2- Nitrothiophen ,Phenylqceto-nitrile and P-toluenesulfonyl chloride.TTPA was characterized by FTIR1HNMR and UV absorption spectra. Real time infrared spectroscopy(RTIR) was used to investigate the effect of different monomers system and different concentrations of TTPA on the polymerization kinetics. The results showed that with the concentration of TTPA increase, with limits, the rate of photopolymerization(Rp) and final double bond conversion increased and the induction period shortened.

  5. Identification of a new sulfonic acid metabolite of metolachlor in soil

    USGS Publications Warehouse

    Aga, D.S.; Thurman, E.M.; Yockel, M.E.; Zimmerman, L.R.; Williams, T.D.

    1996-01-01

    An ethanesulfonic acid metabolite of metolachlor (metolachlor ESA) was identified in soil-sample extracts by negative-ion, fast-atom bombardment mass spectrometry (FAB-MS) and FAB tandem mass spectrometry (FAB-MS/MS). Production fragments from MS/MS analysis of the deprotonated molecular ion of metolachlor ESA in the soil extract can be reconciled with the structure of the synthesized standard. The elemental compositions of the (M - H)- ions of the metolachlor ESA standard and the soil-sample extracts were confirmed by high-resolution mass spectrometry. A dissipation study revealed that metolachlor ESA is formed in soil under field conditions corresponding to a decrease in the concentration of the parent herbicide, metolachlor. The identification of the sulfonated metabolite of metolachlor suggests that the glutathione conjugation pathway is a common detoxification pathway shared by chloroacetanilide herbicides.

  6. Assessment of perfluorooctanoic acid and perfluorooctane sulfonate in surface water - Tamil Nadu, India.

    PubMed

    Sunantha, Ganesan; Vasudevan, Namasivayam

    2016-08-15

    As an emerging class of environmentally persistent organic pollutants, perfluorinated compounds (PFCs), particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS); have been universally found in the environment. Wastewater and untreated effluents are likely the major causes for the accumulation of PFCs in surface water. There are very few reports on the contamination of PFCs in the developing countries, particularly in India. This study reports the quantitative analysis of PFOA and PFOS in Noyyal, Cauvery, and also lakes in and around Chennai, using Ultra-Fast liquid chromatograph. The concentration of PFOA and PFOS ranged from 4 to 93ng/L and 3 to 29ng/L, respectively. The concentration of PFOS was below detectable limit in Cauvery River. A reliable concentration of PFOA was recorded at all sites of River Cauvery (5ng/L). The present study could be useful for the assessment of future monitoring programs of PFOA and PFOS in the surface water. PMID:27216042

  7. Chemorheology of phenylboronate-salicylhydroxamate crosslinked hydrogel networks with a sulfonated polymer backbone

    PubMed Central

    Roberts, Meredith C.; Mahalingam, Alamelu; Hanson, Melissa C.; Kiser, Patrick F.

    2012-01-01

    Hydrogel networks crosslinked with polymer-bound phenylboronic acid (PBA) and salicylhydroxamic acid (SHA) demonstrate pH-reversible gel behavior due to the pH-dependent equilibrium of the crosslinking moieties that form the gel network. Furthermore, the pH at which gels behave dynamically can be controlled by use of a polyelectrolyte backbone. Here we report on the frequency-dependent chemorheological characterization of PBA-SHA crosslinked hydrogel networks with a sulfonated polymer backbone. Our results suggest that the anionic nature of the polymers allows reversible crosslinking at neutral pH that an otherwise neutral-backboned PBA-SHA crosslinked network cannot, and that these charge-induced dynamics can be effectively screened by ions in solution. Moreover, moduli-frequency data can effectively be reduced into a single master curve with a neutral-backboned PBA-SHA gel data set as the reference condition. PMID:23132956

  8. Inhibition of mild steel corrosion by sodium dodecyl benzene sulfonate and sodium oleate in acidic solutions

    SciTech Connect

    Luo, H.; Han, K.N.; Guan, Y.C.

    1998-08-01

    Inhibition of mild steel corrosion by sodium dodecyl benzene sulfonate (C{sub 12}H{sub 25}C{sub 6}H{sub 4}SO{sub 3}Na [SDBS]) and sodium oleate (CH{sub 3}[CH{sub 2}]{sub 7}CH{double_bond}CH[CH{sub 2}]{sub 7}COONa) in acidic solutions was investigated using a potentiostat, a lock-in amplifier, a contact angle goniometer, A fourier transform infrared (FTIR) spectrometer, and an ultraviolet (UV)/visible spectrophotometer. In the presence of the organic inhibitors, the corrosion rate was reduced significantly, Anionic SDBS was adsorbed on the positively charged mild steel surface through the electrostatic attraction. However, for sodium oleate, the soluble oleic acid (CH{sub 3}[CH{sub 2}]{sub 7}CH{double_bond}CH[CH]{sub 7}COOH) chemisorbed on the steel surface at the first stage. Then, insoluble colloid adsorbed on the chemisorbed surface through van der Waals forces.

  9. Chemical doping of MoS2 multilayer by p-toluene sulfonic acid

    NASA Astrophysics Data System (ADS)

    Andleeb, Shaista; Singh, Arun Kumar; Eom, Jonghwa

    2015-06-01

    We report the tailoring of the electrical properties of mechanically exfoliated multilayer (ML) molybdenum disulfide (MoS2) by chemical doping. Electrical charge transport and Raman spectroscopy measurements revealed that the p-toluene sulfonic acid (PTSA) imposes n-doping in ML MoS2. The shift of threshold voltage for ML MoS2 transistor was analyzed as a function of reaction time. The threshold voltage shifted toward more negative gate voltages with increasing reaction time, which indicates an n-type doping effect. The shift of the Raman peak positions was also analyzed as a function of reaction time. PTSA treatment improved the field-effect mobility by a factor of ~4 without degrading the electrical characteristics of MoS2 devices.

  10. Nanoscale Distribution of Sulfonic Acid Groups Determines Structure and Binding of Water in Nafion Membranes.

    PubMed

    Ling, Xiao; Bonn, Mischa; Parekh, Sapun H; Domke, Katrin F

    2016-03-14

    The connection between the nanoscale structure of two chemically equivalent, yet morphologically distinct Nafion fuel-cell membranes and their macroscopic chemical properties is demonstrated. Quantification of the chemical interactions between water and Nafion reveals that extruded membranes have smaller water channels with a reduced sulfonic acid head group density compared to dispersion-cast membranes. As a result, a disproportionally large amount of non-bulk water molecules exists in extruded membranes, which also exhibit larger proton conductivity and larger water mobility compared to cast membranes. The differences in the physicochemical properties of the membranes, that is, the chemical constitution of the water channels and the local water structure, and the accompanying differences in macroscopic water and proton transport suggest that the chemistry of nanoscale channels is an important, yet largely overlooked parameter that influences the functionality of fuel-cell membranes. PMID:26895211

  11. (4-Benzyl-2-oxo-1,3-oxazolidin-5-yl)methyl methane­sulfonate

    PubMed Central

    Cunico, Wilson; Gomes, Claudia R. B.; Tiekink, Edward R. T.; Vellasco Junior, Walcimar T.; Wardell, James L.; Wardell, Solange M. S. V.

    2010-01-01

    The title compound, C12H15NO5S, features an approximately planar five-membered oxazolidin ring (r.m.s. deviation = 0.045 Å) with the peripheral benzyl and methyl methane­sulfonate residues lying to either side of the plane. In the crystal, N—H⋯O hydrogen bonds, involving one of the sulfur-bound oxo groups as acceptor, lead to the formation of supra­molecular chains along the b axis. These chains are reinforced by C—H⋯O contacts with the carbonyl O atom accepting three such inter­actions. The structure was refined as a racemic twin, with the major component being present 89% of the time. PMID:21579707

  12. R22(8) motifs in Aminopyrimidine sulfonate/carboxylate interactions: Crystal structures of pyrimethaminium benzenesulfonate monohydrate (2:2:1) and 2-amino-4,6-dimethylpyrimidinium sulfosalicylate dihydrate (4:2:2)

    PubMed Central

    Balasubramani, Kasthuri; Muthiah, Packianathan Thomas; Lynch, Daniel E

    2007-01-01

    Background Pyrimethamine [2,4-diamino-5-(p-chlorophenyl)-6-ethylpyrimidine] is an antifolate drug used in anti-malarial chemotherapy. Pyrimidine and aminopyrimidine derivatives are biologically important compounds owing to their natural occurrence as components of nucleic acids. Results In the crystal structures of two organic salts, namely pyrimethaminium benzenesulfonate monohydrate 1 and 2-amino-4, 6-dimethylpyrimidinium 3-carboxy-4-hydroxy benzenesulfonate dihydrate 2, pyrimethamine (PMN) and 2-amino-4,6-dimethylpyrimidine (AMPY) are protonated at one of the nitrogens in the pyrimidine rings. In both the PMN and AMPY sulfonate complexes, the protonated pyrimidine rings are hydrogen bonded to the sulfonate groups, forming a hydrogen-bonded bimolecular ring motif with graph-set notation R22(8). The sulfonate group mimics the carboxylate anion's mode of association, which is more commonly seen when binding with 2-aminopyrimidines. In compound 1, the PMN moieties are centrosymmetrically paired through a complementary DADA array of hydrogen bonds. In compound 2, two types of bimolecular cyclic hydrogen bonded R22(8) motifs (one involving the carboxylate group and the other involving sulfonate group) coexist. Furthermore, this compound is stabilized by intra and intermolecular O-H...O hydrogen bonds. Conclusion The crystal structures of pyrimethaminium benzenesulfonate monohydrate and 2-amino-4,6-dimethylpyrimidinium sulfosalicylate dihydrate have been investigated in detail. In compound 1, the R22(8) motif involving the sulfonate group is present. The role the sulfonic acid group plays in mimicking the carboxylate anions is thus evident. In compound 2, two types of bimolecular cyclic hydrogen bonded R22(8) motifs (one involving the carboxylate group and the other involving sulfonate group) coexist. In both the compounds base pairing also occurs. Thus homo and hetero synthons are present. PMID:17999751

  13. Celecoxib influences steroid sulfonation catalyzed by human recombinant sulfotransferase 2A1

    PubMed Central

    Ambadapadi, Sriram; Wang, Peter L.; Palii, Sergiu P.; James, Margaret O.

    2015-01-01

    Celecoxib has been reported to switch the human SULT2A1-catalyzed sulfonation of 17βestradiol (17β-E2) from the 3- to the 17-position. The effects of celecoxib on the sulfonation of selected steroids catalyzed by human SULT2A1 were assessed through in vitro and in silico studies. Celecoxib inhibited SULT2A1-catalyzed sulfonation of dehydroepiandrosterone (DHEA), androst-5-ene-3β, 17β-diol (AD), testosterone (T) and epitestosterone (Epi-T) in a concentration-dependent manner. Low μM concentrations of celecoxib strikingly enhanced the formation of the 17-sulfates of 6-dehydroestradiol (6D-E2), 17β-dihydroequilenin (17β-Eqn), 17β-dihydroequilin (17β-Eq), and 9-dehydroestradiol (9D-E2) as well as the overall rate of sulfonation. For 6D-E2, 9D-E2 and 17β-Eqn, celecoxib inhibited 3-sulfonation, however 3-sulfonation of 17β-Eq was stimulated at celecoxib concentrations below 40 μM. Ligand docking studies in silico suggest that celecoxib binds in the substrate-binding site of SULT2A1 in a manner that prohibits the usual binding of substrates but facilitates, for appropriately shaped substrates, a binding mode that favors 17-sulfonation. PMID:25960318

  14. Use of ammonium chloride solutions to remove sulfonate surfactants from crude oil

    SciTech Connect

    Wolf, N.O.

    1988-08-23

    This patent describes a method for removal of sulfonate surfactants having a molecular weight of about 600 gram/equivalents or less from crude oil or crude oil emulsions containing from 50 parts per million up to 15 weight percent the surfactants, comprising (a) adding a synthetic brine having a NH/sub 4//sup +/ concentration of from about 0.005 molar to about 0.1 molar to crude oil or crude oil emulsions containing the sulfonate surfactants, the brine comprising water and at least one salt selected from the group consisting of (NH/sub 4/)/sub n/X, where X is at least one ion selected from the group consisting of sulfate, nitrate or halide and n is the valence of X, the brine being prepared from fresh water containing substantially no detrimental salts selected from the group consisting essentially of Na, Mg, Al, Ca, Zn, and Ba salts; (b) agitating at a temperature of from about 90F to about 150F the crude oil or crude oil emulsions containing sulfonate surfactants and synthetic brine to ensure thorough mixing and react the NH/sub 4//sup +/ with the sulfonate surfactants and produce a mixture containing water soluble ammonium sulfonate, and (c) allowing the mixture of (b) to separate into aqueous and organic phases, the aqueous phase containing predominantly brine and ammonium sulfonate, and removing the aqueous phase containing predominately brine and sulfonates from the organic phase containing predominately crude oil.

  15. A model survey meter using undoped poly (ether sulfone)

    NASA Astrophysics Data System (ADS)

    Nakamura, Hidehito; Shirakawa, Yoshiyuki; Kanayama, Masaya; Sato, Nobuhiro; Kitamura, Hisashi; Takahashi, Sentaro

    2015-04-01

    The large region surrounding the damaged Fukushima Daiichi Nuclear Power Plant has necessitated the use of numerous radiation survey meters with large, robust substrates. The survey meters require efficient scintillation materials that do not require doping and have dimensional stability, such as poly (ether sulfone) (PES) resins. Here, we demonstrate the performance of a model survey meter that uses large PES plates with polished, mirrored surfaces and rough, scattering surfaces. Light collection efficiencies from plates having one or more of these surfaces were quantitatively Characterised with 36Cl-, 60Co-, 137Cs-radioactive sources. The count rates of plates having a combination of mirrored/scattering-surfaces are >1.6 times that for plates having two mirrored surfaces. In addition, a significant amount of radiation-induced light generated in the PES is trapped inside the plate because of its relatively high refractive index. The results indicate that large, undoped PES plates can be used in radiation survey meters.

  16. Electrochemical Studies of Ceramic Carbon Electrodes Prepared with Sulfonated Organosilane Precursors

    NASA Astrophysics Data System (ADS)

    Eastcott, Jennie

    State-of-the-art electrodes for proton exchange membrane fuel cells (PEMFCs) contain platinum catalyst and a Nafion proton-conducting binder. Optimal conditions for Nafion functionality are at 80°C and 100% relative humidity (RH). Ceramic carbon electrodes (CCEs), consisting of carbon particles supported by ceramic binder network, may be an alternative electrode structure which replaces Nafion with organosilane materials. CCEs are also attractive for their high surface area and durable nature. CCEs have been fabricated via an in-situ sol-gel polymerization process. Development of a novel electrode fabrication procedure included direct spray-deposition of CCEs onto a microporous/gas diffusion layer to facilitate adhesion and facile electrode preparation. CCEs were composed of commercial carbon-supported platinum catalyst and 3-trihydroxysilyl-1-propanesulfonic acid (TPS) or TPS and tetraethylorthosilicate (TEOS) to vary the level of sulfonation. CCEs were initially tested electrochemically in a half-cell set-up to evaluate electrode functionality. An optimal loading of 42-48 wt% silane was determined for CCEs with only TPS to provide the highest electrochemically active surface area (ECSA) of platinum and proton conductivity. BET surface areas were low due to restriction of pore sizes by the sulfonated side chain. Composite CCEs of TPS/TEOS had enhanced electrochemical performance and high BET surface areas (>400 m 2 g-1), indicating high porosity. Excellent electrochemical results were obtained for the CCE with a TPS:TEOS ratio of 4:96 (40 wt% total silane). The sulfonated TPS/TEOS CCE (SS-CCE) was further evaluated in a fuel cell. Electrochemical studies showcased higher accessibility of catalyst sites and good proton conductivity compared to Nafion-containing cathodes. At 80°C and 100% relative humidity (RH), CCEs performed similarly to Nafion electrodes at low current density but suffered from mass transport limitations due to flooding at high current density

  17. Aerobic Biotransformation of Fluorotelomer Thioether Amido Sulfonate (Lodyne) in AFFF-Amended Microcosms.

    PubMed

    Harding-Marjanovic, Katie C; Houtz, Erika F; Yi, Shan; Field, Jennifer A; Sedlak, David L; Alvarez-Cohen, Lisa

    2015-07-01

    The aerobic biotransformation pathways of 4:2, 6:2, and 8:2 fluorotelomer thioether amido sulfonate (FtTAoS) were characterized by determining the fate of the compounds in soil and medium microcosms amended with an aqueous film-forming foam (AFFF) solution. The biotransformation of FtTAoS occurred in live microcosms over approximately 40 days and produced 4:2, 6:2, and 8:2 fluorotelomer sulfonate (FtS), 6:2 fluorotelomer unsaturated carboxylic acid (FtUCA), 5:3 fluorotelomer carboxylic acid (FtCA), and C4 to C8 perfluorinated carboxylic acids (PFCAs). Two biotransformation products corresponding to singly and doubly oxygenated forms of 6:2 FtTAoS were also identified through high resolution mass spectrometry (MS) analysis and liquid chromatography tandem-MS. An oxidative assay was used to indirectly quantify the total concentration of polyfluorinated compounds and check the mass balance. The assay produced near complete mass recovery of FtTAoS after biotransformation, with 10% (mol/mol) of the amended FtTAoS accounted for in FtS, FtCA, and PFCA products. The transformation rates of identified products appear to be slow relative to FtTAoS, indicating that some intermediates may persist in the environment. This study confirms some of the sources of FtS and PFCAs in groundwater and soil at AFFF-impacted sites and suggests that fluorinated intermediates that are not routinely measured during the biotransformation of PFASs may accumulate. PMID:26042823

  18. Layered solids based on second-sphere coordination interactions: synthesis, spectroscopic characterization, crystal structure and packing of two copper(II) naphthalene-2-sulfonates

    NASA Astrophysics Data System (ADS)

    Sharma, Raj Pal; Sharma, Rajni; Bala, Ritu; Rychlewska, Urszula; Warżajtis, Beata

    2005-03-01

    [Cu(H 2O) 6](C 10H 7SO 3) 21 was obtained from reaction of CuCO 3·Cu(OH) 2 and naphthalene-2-sulphonic acid in aqueous medium in 1:4 molar ratio. It crystallizes in the monoclinic space group P2 1/ n with a=7.0582(3) Å, b=6.2666(3) Å, and c=27.1420(10) Å, β=92.678(4)°, Z=2. The structure was determined from 1986 observed reflections and refined to R=0.033. When ethylenediamine was added to hexaaquacopper(II) naphthalene-2-sulfonate dissolved in water, [Cu(en) 2(H 2O) 2](C 10H 7SO 3) 22 was obtained which crystallizes in the triclinic space group P1¯ with a=7.1491(5) Å, b=7.1949(5) Å, and c=14.6500(10) Å, α=99.025(6)°, β=98.976(6)°, and γ=104.262(6)°, Z=1. The structure was determined from 2296 observed reflections and refined to R=0.0313. X-ray structure determination of 1 revealed an ionic structure consisting of [Cu(H 2O) 6] +2 and two naphthalene-2-sulfonate anions while that of 2 contains [Cu(en) 2(H 2O) 2] 2+ cation and two naphthalene-2-sulfonate anions. Characteristic for the studied crystals is the alternated-layer arrangement of complex cations and naphthalene-2-sulfonate anions, linked together via hydrogen bonding, and the presence of a particularly robust R22(8) hydrogen-bonding motif that joins the complex cation with two oxygen atoms of the same sulfonate group. Elemental analyses, IR, UV/vis spectroscopic studies are consistent with the structures revealed by X-ray structure determination.

  19. Oxidative stress and histopathology damage related to the metabolism of dodecylbenzene sulfonate in Senegalese sole.

    PubMed

    Alvarez-Muñoz, D; Gómez-Parra, A; Blasco, J; Sarasquete, C; González-Mazo, E

    2009-03-01

    Surfactants such as linear alkylbenzene sulfonates (LAS) are widely utilised in the formulation of detergents in commercial products. After use, they pass through waste water treatment plants (WWTP) and are then discharged to aquatic ecosystems, causing risk to aquatic life. The exposure of marine animals to these compounds enhances the production of reactive oxygen species (ROS) with subsequent damage to macromolecules, and produces histological alterations. A flow-through experiment with Senegalese sole (Solea senegalensis) has been devised with the object of correlating the metabolism of LAS including sulfophenylcarboxylic acids (SPCs) by fish with their antioxidant defence system (generation of oxyradicals) and histopathological damage. The generation of intermediate degradation products (SPCs) by the organism, the histopathological responses, the antioxidant enzymes (catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione S-transferase (GST)), as well as other kinds of enzyme such as acid and alkaline phosphatases (AcP, ALP), were measured. SPCs from 5ØC(6) to 11ØC(12) were identified and quantified in fish and water; their concentrations differed depending on the sampling moment. In general, the responses found in the enzymes were slight: a decrease in the enzymatic activity in gills and activation in the digestive tract. The evidence of histopathological damage identified was also small; the organism's defensive mechanism against pollutants should enable it to recover easily. A direct relationship was established between biotransformation and the generation of SPCs and ROS. In conclusion, the correct functioning of the antioxidant defence system with absence of large variations, the short-term histopathological damage, and the evidence of SPCs indicate an adequate metabolism of 2-phenyl-C(12)-linear alkylbenzene sulfonates (2ØC(12)LAS) by this specie and non-toxic effects at environmentally realistic levels. PMID:19121837

  20. Assessing the toxicity of dodecylbenzene sulfonate to the midge Chironomus riparius using body residues as the dose metric.

    PubMed

    Hwang, Haejo; Fisher, Susan W; Kim, Kyeok; Landrum, Peter F; Larson, Robert J; Versteeg, Donald J

    2003-02-01

    Dodecylbenzene sulfonate (DBS) is a component of linear alkylbenzene sulfonate (LAS), an anionic surfactant, mainly used in household detergents. Due to the large quantity of DBS in use, there is concern over adverse environmental effects. This work examined the toxicokinetics and toxicity of the 2-phenyl isomer of dodecylbenzene sulfonate in 4-d, 10-d, and partial life-cycle tests on the midge, Chironomus riparius, exposed to aqueous solutions. Toxicokinetics were determined in 10-d uptake and 5-d elimination tests. The toxicokinetics were based on parent compound concentration in water and yielded an uptake coefficient (ku) of 17.5 (14.87-20.20) ml/g/h, an elimination rate constant (ke) of 0.073 (0.062-0.085) per h, a bioconcentration factor (BCF) of 56 to 240, and a half-life (t 1/2) of 9.5 (8.0-11.0) h. Biotransformation measurements did not reveal evidence for DBS metabolism. Thus, body residues, determined in the toxicity study, represent parent compound. In toxicity tests, 4- and 10-d LR50s (the body residue required to cause 50% mortality) in live midges were 0.72 (0.65-0.79) and 0.18 (0.08-0.42) mmol/kg, respectively. Thirty-day LR50s were 0.18 (0.09-1.64) and 0.21 (0.15-0.39) mmol/kg in duplicate studies. Of the sublethal endpoints, only developmental time increase was significant, with the lowest-observed-effect residues of 0.085 (0.067-0.105) and 0.100 (0.087-0.114) mmol/kg for male and female midges, respectively. Deformities in surviving larvae were also observed as chronic responses for body residues exceeding the 30-d LR50. The body residues required for mortality suggest that DBS acts like a polar narcotic in the midge. PMID:12558161

  1. Utilization of common ditch vegetation in the reduction of fipronil and its sulfone metabolite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fipronil, a phenylpyrazole insecticide and its oxidative sulfone metabolite are two potential nonpoint source pollutants from treated rice and cotton production. A consequence of these pollutants occurring in surface runoff is degradation of downstream aquatic ecosystems. Utilization of primary inte...

  2. REVISITING NUCLEOPHILIC SUBSTITUTION REACTIONS: MICROWAVE-ASSISTED SYNTHESIS OF AZIDES, THIOCYANATES AND SULFONES IN AQUEOUS MEDIUM

    EPA Science Inventory

    A practical, rapid and efficient microwave (MW) promoted synthesis of various azides, thiocyanates and sulfones, is described in aqueous medium. This general and expeditious MW-enhanced nucleophilic substitution approach uses easily accessible starting materials such as halides o...

  3. Magnetite-supported sulfonic acid: a retrievable nanocatalyst for the Ritter reaction and multicomponent reactions

    EPA Science Inventory

    Magnetite-sulfonic acid (NanocatFe-OSO3H), prepared by wet-impregnation method, serves as a magnetically retrievable sustainable catalyst for the Ritter reaction which can be used in several reaction cycles without any loss of activity.

  4. EFFECTS OF PRENATAL PERFLUOROOCTANE SULFONATE (PFOS) EXPOSURE ON LUNG MATURATION IN THE PERINATAL RAT

    EPA Science Inventory

    Background: Perfluorooctane sulfonate (PFOS), found widely in wildlife and humans, is environmentally and metabolically stable. Environmental PFOS may be from its use as a surfactant, hydrolysis of perfluorooctanesulfonyl fluoride, and degradation of N-alkyl-perfluorooctanesulfon...

  5. Synthesis and characterizations of electrospun sulfonated poly (ether ether ketone) SPEEK nanofiber membrane

    NASA Astrophysics Data System (ADS)

    Hasbullah, N.; Sekak, K. A.; Ibrahim, I.

    2016-07-01

    A novel electrospun polymer electrolyte membrane (PEM) based on Sulfonated Poly (ether ether ketone) were prepared and characterized. The poly (ether ether ketone) PEEK was sulfonated using concentrated sulfuric acid at room temperature for 60 hours reaction time. The degree sulfonation (DS) of the SPEEK are 58% was determined by H1 NMR using area under the peak of the hydrogen shielding at aromatic ring of the SPEEK. Then, the functional group of the SPEEK was determined using Fourier transfer infrared (FTIR) showed O-H vibration at 3433 cm-1 of the sulfonated group (SO2-OH). The effect of the solvent and polymer concentration toward the electrospinning process was investigated which, the DMAc has electrospun ability compared to the DMSO. While, at 20 wt.% of the polymer concentration able to form a fine and uniform nanofiber, this was confirmed by FESEM that shown electrospun fiber mat SPEEK surface at nano scale diameter.

  6. Titania-based molecularly imprinted polymer for sulfonic acid dyes prepared by sol-gel method.

    PubMed

    Li, Man; Li, Rong; Tan, Jin; Jiang, Zi-Tao

    2013-03-30

    A novel titania-based molecularly imprinted polymer (MIP) was synthesized through sol-gel process with sunset yellow (Sun) as template, without use of functional monomer. MIP was used as a solid-phase extraction material for the isolation and enrichment of sulfonic acid dyes in beverages. The results showed that MIP exhibited better selectivity, higher recovery and adsorption capacity for the sulfonic acid dyes compared to the non-imprinted polymer (NIP). MIP presented highest extraction selectivity to Sun when pH less than or equal to 3. The adsorption capacity was 485.9 mg g(-1), which was larger than that of NIP (384.7 mg g(-1)). The better clean-up ability demonstrated the capability of MIP for the isolation and enrichment of sulfonic acid dyes in complicated food samples. The mean recoveries for the sulfonic acid dyes on MIP were from 81.9% to 97.2% in spiked soft drink. PMID:23598213

  7. Effect of sulfonation and diethanolamine addition on the mechanical and physicochemical properties of SEPS copolymer

    NASA Astrophysics Data System (ADS)

    Patiño, D.; Correa, E.; Acevedo-Morantes, M.

    2016-02-01

    Modification techniques have been developed to achieve changes in the processing of polymers, and modification of their mechanical, thermal and morphological properties, as well as their hydrophobicity and conductivity. Sulfonation improves ion conductivity, antistatic behaviour, hydrophilicity and solubility of the polymers. These characteristics are related to the presence of sulfonic groups in the polymer matrix. This research project focuses on the evaluation of mechanical, physical and chemical properties of membranes that are based on a sulfonated Styrene-Ethylene-Propylene-Styrene (SEPS) copolymer. The membranes were functionalized with diethanolamine at 5, 15 and 30% w/w, to separate carbon dioxide. FTIR and XRD analyses were used to characterize the membranes. The sulfonated-loaded membrane with 15% of diethanolamine showed the best results in each characterization.

  8. Anhydrous state proton and lithium ion conducting solid polymer electrolytes based on sulfonated bisphenol-A-poly(arylene ethers)

    NASA Astrophysics Data System (ADS)

    Guha Thakurta, Soma

    Sulfonated polymer based solid polymer electrolytes (SPEs) have received considerable interest in recent years because of their wide variety of applications particularly in fuel cells, batteries, supercapacitors, and electrochromic devices. The present research was focused on three interrelated subtopics. First, two different bisphenol-A-poly(arylene ethers), polyetherimide (PEI) and polysulfone (PSU) were sulfonated by a post sulfonation method to various degrees of sulfonation, and their thermal and mechanical properties were examined. The effects of poly(arylene ether) chemical structure, reaction time, concentration, and types of sulfonating agents on sulfonation reaction were investigated. It was found that deactivation of bisphenol A unit caused by the electron withdrawing imide, retarded the sulfonation of PEI compared to PSU. Sulfonation conducted with a high concentration of sulfonating agent and/or prolonged reaction time exhibited evidence of degradation at the isopropylidene unit. The degradation occurred through the same mechanistic pathway with the two different sulfonating agents, chlorosulfonic acid (CSA) and trimethylsilyl chlorosulfonate (TMSCS). The degradation was faster with CSA than its silyl ester, TMSCS, and was evident even at low acid concentration. Second, novel anhydrous proton conducting solid polymer electrolytes (SPEs) were prepared by the incorporation of 1H-1,2,4-triazole (Taz) as a proton solvent in sulfonated polyetherimide (SPEI) matrix. The size, shape, and state of dispersion (crystal morphology) of triazole crystals in SPEI were examined as a function of degree of sulfonation and triazole concentration. Increasing sulfonic acid content caused reduction of triazole crystallite size, hence the depression of melting temperature and their uniform distribution throughout the sulfonated polymer matrix. The increased rate of structure diffusion within the smaller size crystals due to the improved molecular mobility contributed

  9. Design and Development of Highly Sulfonated Polymers as Proton Exchange Membranes for High Temperature Fuel Cell Applications

    NASA Astrophysics Data System (ADS)

    Dang, Thuy D.; Bai, Zongwu; Yoonessi, Mitra

    A series of high molecular weight, highly sulfonated poly(arylenethioethersulfone) (SPTES) polymers were synthesized by polycondensation, which allowed controlled sulfonation of up to 100 mol %. The SPTES polymers were prepared via step growth polymerization of sulfonated aromatic difluorosulfone, aromatic difluorosulfone, and 4,4 '-thiobisbenzenthiol in sulfolane solvent at the temperature up to 180 °C. The composition and incorporation of the sulfonated repeat unit into the polymers were confirmed by 1H nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. Solubility tests on the SPTES polymers confirmed that no cross-linking and probably no branching occurred during the polymerizations. The end-capping groups were introduced in the SPTES polymers to control the molecular weight distribution and reduce the water solubility of the polymers. Tough, ductile membranes formed via solvent-casting exhibited increased water absorption with increasing degrees of sulfonation. The polymerizations conducted with the introduction of end-capping groups resulted in a wide variation in polymer proton conductivity, which spanned a range of 100 -300 mS cm-1, measured at 65 °C and 85 % relative humidity. The measured proton conductivities at elevated temperatures and high relative humidities are up to three times higher than that of the state-of-the-art Nafion-H proton exchange membrane under nearly comparable conditions. The thermal and mechanical properties of the SPTES polymers were investigated by TGA, DMA, and tensile measurements. The SPTES polymers show high glass transition temperatures (Tg), ˜220 °C, depending on the degree of sulfonation in polymerization. SPTES-50 polymer shows a Tg of 223 °C, with high tensile modulus, high tensile strengths at break and at yield as well as elongation at break. Wide angle X-ray scattering of the polymers shows two broad scattering features centered at 4.5 Å and 3.3 Å, the latter peak being

  10. Asymmetrical Self-assembly From Fluorinated and Sulfonated Block Copolymers in Aqueous Media

    SciTech Connect

    Wang, Xiaojun; Hong, Kunlun; Baskaran, Durairaj; Goswami, Monojoy; Sumpter, Bobby G; Mays, Jimmy

    2011-01-01

    Block copolymers of fluorinated isoprene and partially sulfonated styrene form novel tapered rods and ribbon-like micelles in aqueous media due to a distribution of sulfonation sites and a large Flory-Huggins interaction parameter. A combination of microscopy, light scattering, and simulation demonstrates the presence of these unique nanostructures. This study sheds light on the micellization behavior of amphiphilic block polymers by revealing a new mechanism of self-assembly.

  11. Synthesis, structure, theoretical calculations and biological activity of sulfonate active ester new derivatives

    NASA Astrophysics Data System (ADS)

    Ghazzali, Mohamed; Khattab, Sherine A. N.; Elnakady, Yasser A.; Al-Mekhlafi, Fahd A.; Al-Farhan, Khalid; El-Faham, Ayman

    2013-08-01

    A series of naphthyl and tolyl sulfonate ester were synthesized and characterized by H NMR. X-ray single crystal diffraction experiments established the molecular structure of three new sulfonate esters derivatives, and spectral data agree with these in solution. The observed hydrogen bonding is discussed on the basis of crystal structural analyses and DFT/MP2 geometry optimization quantum calculations. Antimicrobial activities were screened for selected compounds against three human cancer cell lines and Mosquito Culex pipiens larvae.

  12. Viscoelastic Behavior of Low Molecular Weight Sulfonated Polystyrene Ionomers

    NASA Astrophysics Data System (ADS)

    Zhao, Hongying

    Ionomers are those hydrophobic polymers having small amounts of bonded ionic groups. The introduction of the ionic groups into polymer chain produces large changes in the physical, mechanical and rheological properties of the parent polymer. Characterization of the effect of the ionic interactions on the rheology is complicated by the difficulty in separating effects due to molecular entanglements and the ionic interactions. In this study, low molecular weight (Mw=4000) sulfonated polystyrene (SPS) was used to study the dynamic and steady shear rheology of SPS ionomers. The polymer chain length used was far below the entanglement molecular weight of polystyrene and effects of molecular entanglements will be absent. Any polymer chain entanglements or lengthening behavior on the melt rheology should be due to the ionic interactions. Random SPS ionomers with two sulfonation levels were examined, 2.5 and 4.8 mol%, which corresponded, respectively, to one and two sulfonate groups per chain on average. The metal counterions was varied across the alkali metal series of the periodic table. Morphology of the ionomer was characterized by using small angle x-ray scattering (SAXS) analysis, and dynamic and steady shear measurements were performed to investigate rheological behavior of the ionomers. Glass transition temperatures of the ionomers increased with increasing ion concentration but were insensitive to cation used. The scattering peak in SAXS indicates the existence of the nanophase separated ionic clusters. The strong ionic nanophase persist up to very high temperatures and is not sensitive to the external stress. Time-temperature superposition (TTS) of G' worked reasonably well while TTS of G" failed for most ionomers. Ionic interactions increased the terminal relaxation time of the melts as much as seven orders of magnitude greater than the unentangled PS melt. The zero shear viscosity and first normal stress coefficients scaled with cq/a, where c was the

  13. Composite proton exchange membrane based on sulfonated organic nanoparticles

    NASA Astrophysics Data System (ADS)

    Pitia, Emmanuel Sokiri

    As the world sets its sight into the future, energy remains a great challenge. Proton exchange membrane (PEM) fuel cell is part of the solution to the energy challenge because of its high efficiency and diverse application. The purpose of the PEM is to provide a path for proton transport and to prevent direct mixing of hydrogen and oxygen at the anode and the cathode, respectively. Hence, PEMs must have good proton conductivity, excellent chemical stability, and mechanical durability. The current state-of-the-art PEM is a perfluorosulfonate ionomer, Nafion®. Although Nafion® has many desirable properties, it has high methanol crossover and it is expensive. The objective of this research was to develop a cost effective two-phase, composite PEM wherein a dispersed conductive organic phase preferentially aligned in the transport direction controls proton transport, and a continuous hydrophobic phase provides mechanical durability to the PEM. The hypothesis that was driving this research was that one might expect better dispersion, higher surface to volume ratio and improved proton conductivity of a composite membrane if the dispersed particles were nanometer in size and had high ion exchange capacity (IEC, = [mmol sulfonic acid]/gram of polymer). In view of this, considerable efforts were employed in the synthesis of high IEC organic nanoparticles and fabrication of a composite membrane with controlled microstructure. High IEC, ~ 4.5 meq/g (in acid form, theoretical limit is 5.4 meq/g) nanoparticles were achieved by emulsion copolymerization of a quaternary alkyl ammonium (QAA) neutralized-sulfonated styrene (QAA-SS), styrene, and divinylbenzene (DVB). The effects of varying the counterion of the sulfonated styrene (SS) monomer (alkali metal and QAA cations), SS concentration, and the addition of a crosslinking agent (DVB) on the ability to stabilize the nanoparticles to higher IECs were assessed. The nanoparticles were ion exchanged to acid form. The extent of ion

  14. Investigation of the doping efficiency of poly(styrene sulfonic acid) in poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) dispersions by capillary electrophoresis.

    PubMed

    Diah, Anang W M; Quirino, Joselito P; Belcher, Warwick; Holdsworth, Clovia I

    2014-07-01

    CE can efficiently separate poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT/PSS) complexes and free PSS in dispersions and can be used to estimate the degree of PSS doping. We investigated the doping efficiency of PSS on PEDOT in dispersions using CE and its effect on the conductivity of the resulting PEDOT/PSS films. Results of this study indicate that dispersions containing 1:2.5-3 EDOT:PSS feed ratio (by weight) exhibiting 72-73% PSS doping generate highly processable and highly conductive films. Conductivity can be optimized by limiting the time of reaction to 12 h. At this point of the reaction, the PEDOT/PSS segments, appearing as broad band in the electropherogram, could still exist in an extended coil conformation favoring charge transport resulting in high conductivity. Above a threshold PEDOT length formed at reaction times longer than 12 h, the PEDOT/PSS complex, appearing as spikes in the electropherogram, most likely have undergone a conformational change to coiled core-shell structure restricting charge transport resulting in low conductivity. The optimal conductivity (5.2 S/cm) of films from dispersions synthesized for 12 h is significantly higher than those from its commercial equivalent Clevios P and other reported values obtained under similar conditions without the addition of codopants. PMID:24782292

  15. Vibrational spectroscopic study of pure and silica-doped sulfonated poly(ether ether ketone) membranes

    NASA Astrophysics Data System (ADS)

    Rangasamy, Vijay Shankar; Thayumanasundaram, Savitha; Seo, Jin Won; Locquet, Jean-Pierre

    2015-03-01

    We report the vibrational properties of sulfonated poly(ether ether ketone) (SPEEK) membranes, used as electrolytes in proton exchange membrane (PEM) fuel cells, studied by Fourier transform infrared (FTIR) spectroscopy. We discuss the changes in the vibrational modes of the functional groups present in the polymer arising due to the sulfonation process and the subsequent incorporation of silica particles functionalized with sulfonic acid group. From the infrared spectra, we confirm the incorporation of sulfonic acid group in the polymer chain as well as in the functionalized silica particles. We have also measured the variations in the peak area ratio of the characteristic out-of-plane vibrations of the aromatic rings in the PEEK polymer at 1280 cm-1 with respect to a reference peak at 1305 cm-1. These values were correlated to the crystallinity (XC) values experimentally determined by DSC technique, providing a non-destructive means to calculate the crystallinity of polymer membranes. The calculated XC values were in good agreement with the experimental values. The crystallinity was observed to decrease with increasing degree of sulfonation (DS), indicating the crystalline-to-amorphous phase modification of the polymer by sulfonation, which along with the enhanced ion-exchange capacity and water uptake, is responsible for the improved ionic conductivity at higher DS values.

  16. Single-step synthesis of sulfonated polyoxadiazoles and their use as proton conducting membranes

    NASA Astrophysics Data System (ADS)

    Gomes, Dominique; Roeder, Jerusa; Ponce, Mariela L.; Nunes, Suzana P.

    A single-step approach for the synthesis of sulfonated polyoxadiazoles from hydrazine sulfate was developed using non-sulfonated diacids in polyphosphoric acid. The post-sulfonation conditions were optimized by varying reaction time, medium and reagent concentrations in sulfuric acid, oleum and/or their mixtures. For the first time, a series of sulfonated polyoxadiazoles with ion exchange capacity (IEC) ranging from 1.26 to 2.7 meqiv. g -1 and high molecular weight (about 40,0000 g mol -1) were synthesized. The structures of the polymers were characterized by elemental analysis, 1H NMR, and FTIR. Sulfonated polyoxadiazole membranes with high thermal stability indicated by observed glass-transition temperatures (T g) ranging from 364 to 442 °C in sodium salt form and from 304 to 333 °C in acid form and with high mechanical properties (storage modulus about 3 GPa at 300 °C) have been prepared. The membrane stability to oxidation was investigated by soaking the film in Fenton's reagent at 80 °C for 1 h. The sulfonated polyoxadiazole membranes exhibited high oxidative stability, retaining 98-100% of their weight after the test. Proton conductivity values with the order of magnitude of 10 -1 to 10 -2 S cm -1 at 80 °C and with relative humidity ranging from 100% to 20% were obtained.

  17. Polymer electrolytes based on sulfonated polysulfone for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Lufrano, F.; Baglio, V.; Staiti, P.; Arico', A. S.; Antonucci, V.

    This paper reports the development and characterization of sulfonated polysulfone (SPSf) polymer electrolytes for direct methanol fuel cells. The synthesis of sulfonated polysulfone was performed by a post sulfonation method using trimethyl silyl chlorosulfonate as a mild sulfonating agent. Bare polysulfone membranes were prepared with two different sulfonation levels (60%, SPSf-60 and 70%, SPSf-70), whereas, a composite membrane of SPSf-60 was prepared with 5 wt% silica filler. These membranes were investigated in direct methanol fuel cells (DMFCs) operating at low (30-40 °C) and high temperatures (100-120 °C). DMFC power densities were about 140 mW cm -2 at 100 °C with the bare SPSf-60 membrane and 180 mW cm -2 at 120 °C with the SPSf-60-SiO2 composite membrane. The best performance achieved at ambient temperature using a membrane with high degree of sulfonation (70%, SPSf-70) was 20 mW cm -2 at atmospheric pressure. This makes the polysulfone-based DMFC suitable for application in portable devices.

  18. Synthesis of analogs of juvenile hormone on the basis of the telomerization reaction of piperylene with sulfones

    SciTech Connect

    Tolstikov, G.A.; Rozentsvet, O.A.; Pantukh, B.I.; Khalilov, L.M.

    1986-10-20

    In continuing the work on the study of the telomerization of 1,3-dienes with sulfones containing an active H atom, and also with the aim of synthesizing analogs of juvenile hormone (JH) based on the telomers obtained, they studied the catalytic telomerization of 1,3-pentadiene (piperylene) with ..beta..-substituted sulfonates. It was established that trans-piperlyene participates in the telomerization reaction with sulfones in the presence of the catalytic system PdCl/sub 2/(Ph/sub 3/P)/sub 2/-PhONa. Methyl 2-phenylsulfonyl-3,7-dimethyl-4(E), 9-decadienecarboxylate (II) is formed in a yield of 65% by the reaction of methyl phenylsulfonylacetate (I) with piperylene in the course of 20 h at 85/sup 0/C. The presence of absorption bands at 920 (CH/sub 2/=C) and 980 cm/sup -1/ (E-CH=CH) in the IR spectrum of compound (II) and the presence of a group of multiplet signals at delta 4.8-5.3 ppm in the PMR spectrum, corresponding to five protons of double bonds, indicate the addition of two molecules of piperylene to the molecule of the sulfone (I). The oxidation with oxygen on a Pd/Cu-catalyst proceeds smoothly to the methyl ketone (III); this clearly confirms the presence of the terminal C=C bond in the telomer (II). In the PMR spectrum of (II), notice is taken of the group of signals in the region of 3.30-3.53 ppm corresponding to three methoxy protons. There are three pairs of doublets (J = 7 Hz) in the region of 0.1-1.3 ppm which correspond to the methyl group. The complexity of the PMR spectrum is probably explained by the fact that the reaction leads to the formation of a complex mixture of diastereoisomers. As was to be expected, methyl 3,7-dimethyl-4,9-decadienoate (IV) is formed as the sole product with a yield of 70% in the desulfonation of the telomer (II) using Na/Hg in methanol according to the method of (5); the structure of (IV) was established with the aid of /sup 13/C NMR spectroscopy.

  19. Fate of linear alkylbenzene sulfonate in the Mississippi River

    USGS Publications Warehouse

    Tabor, C.F.; Barber, L.B., II

    1996-01-01

    The 2 800-km reach of the Mississippi River between Minneapolis, MN, and New Orleans, LA, was examined for the occurrence and fate of linear alkylbenzene sulfonate (LAS), a common anionic surfactant found in municipal sewage effluents. River water and bottom sediment were sampled in the summer and fall of 1991 and in the spring of 1992. LAS was analyzed using solid- phase extraction/derivatization/gas chromatography/mass spectrometry. LAS was present on all bottom sediments at concentrations ranging from 0.01 to 20 mg/kg and was identified in 21% of the water samples at concentrations ranging from 0.1 to 28.2 ??g/L. The results indicate that LAS is a ubiquitous contaminant on Mississippi River bottom sediments and that dissolved LAS is present mainly downstream from the sewage outfalls of major cities. The removal of the higher LAS homologs and external isomers indicates that sorption and biodegradation are the principal processes affecting dissolved LAS. Sorbed LAS appears to degrade slowly.

  20. Thermoanalytical Investigation of Some Sulfone-Containing Drugs

    PubMed Central

    Salama, Nahla N.; El Ries, Mohammed A.; Toubar, Safaa; Abd El Hamid, Maha; Walash, Mohammed I.

    2012-01-01

    The thermal behavior of some sulfone-containing drugs, namely, dapsone (DDS), dimethylsulfone (MSM), and topiramate (TOP) in drug substances, and products were investigated using different thermal techniques. These include thermogravimetry (TGA), derivative thermogravimetry (DTG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). The thermogravimetric data allowed the determination of the kinetic parameters: activation energy (E a), frequency factor (A), and reaction order (n). The thermal degradation of dapsone and topiramate was followed a first-order kinetic behavior. The calculated data evidenced a zero-order kinetic for dimethylsulfone. The relative thermal stabilities of the studied drugs have been evaluated and follow the order DDS > TOP > MSM. The purity was determined using DSC for the studied compounds, in drug substances and products. The results were in agreement with the recommended pharmacopoeia and manufacturer methods. DSC curves obtained from the tablets suggest compatibility between the drugs, excipients and/or coformulated drugs. The fragmentation pathway of dapsone with mass spectrometry was taken as example, to correlate the thermal decomposition with the resulted MS-EI. The decomposition modes were investigated, and the possible fragmentation pathways were suggested by mass spectrometry. PMID:22792516

  1. Determination of perfluoroalkyl carboxylic, sulfonic, and phosphonic acids in food.

    PubMed

    Ullah, Shahid; Alsberg, Tomas; Vestergren, Robin; Berger, Urs

    2012-11-01

    A sensitive and accurate method was developed and validated for simultaneous analysis of perfluoroalkyl carboxylic acids, sulfonic acids, and phosphonic acids (PFPAs) at low picograms per gram concentrations in a variety of food matrices. The method employed extraction with acetonitrile/water and cleanup on a mixed-mode co-polymeric sorbent (C8 + quaternary amine) using solid-phase extraction. High-performance liquid chromatographic separation was achieved on a C18 column using a mobile phase gradient containing 5 mM 1-methyl piperidine for optimal chromatographic resolution of PFPAs. A quadrupole time-of-flight high-resolution mass spectrometer operating in negative ion mode was used as detector. Method detection limits were in the range of 0.002 to 0.02 ng g(-1) for all analytes. Sample preparation (extraction and cleanup) recoveries at a spiking level of 0.1 ng g(-1) to a baby food composite were in the range of 59 to 98 %. A strong matrix effect was observed in the analysis of PFPAs in food extracts, which was tentatively assigned to sorption of PFPAs to the injection vial in the solvent-based calibration standard. The method was successfully applied to a range of different food matrices including duplicate diet samples, vegetables, meat, and fish samples. PMID:22955674

  2. Phthalocyanines And Their Sulfonated Derivatives As Photosensitizers In Photodynamic Therapy.

    NASA Astrophysics Data System (ADS)

    Riesz, Peter; Krishna, C. Murali

    1988-02-01

    Photodynamic therapy (PDT) of human tumors with hematoporphyrin derivative (HpD) has achieved encouraging results. However, HpD is a complex mixture whose composition varies in different preparations and with time of storage. The future promise of PDT for cancer treatment depends on the development of new chemically defined sensitizers which absorb more strongly than HpD in the 600-800 nm region. A shift to higher wavelengths is desirable since it allows increased light penetration in human tissues. In vivo, these sensitizers should be non-toxic, localize selectively in tumors and generate cytotoxic species upon illumination with a high quantum yield. These damaging species may be singlet oxygen (1O2) produced by the transfer of energy from the triplet state of the sensitizer to oxygen (Type II) or superoxide anion radicals formed by electron transfer to oxygen or substrate radicals generated by electron or hydrogen transfer directly from the sensitizer (Type I). The recent work of several groups indicating that phthalocyanines and their water soluble derivatives are promising candidates for PDT is reviewed. The photophysics, photochemistry, photosensitized killing of cultured mammalian cells and the use for in vivo photodynamic therapy of phthalocyanines is outlined. Our studies of the post-illumination photohemolysis of human red blood cells as a model system for membrane photomodification sensitized by phthalocyanine sulfonates are consistent with the predominant role of 1O2 as the damaging species.

  3. Molecular mobility and cation conduction in sulfonated polyester copolymer ionomers

    NASA Astrophysics Data System (ADS)

    Tudryn, Gregory; King, Daniel; O'Reilly, Michael; Winey, Karen; Colby, Ralph

    2011-03-01

    Poly(ethylene oxide) ionomers are candidate materials for electrolytes in energy storage devices due to the ability of ether oxygen to solvate cations. Copolyester ionomers are synthesized via condensation of sulfonated phthalates with mixtures of PEG and PTMG to make random copolymer ionomers with identical ion content. Variation of the PEG/PTMG composition changes Tg, dielectric constant and ionic aggregation; each with consequences for ion transport. Dielectric spectroscopy is used to determine number density of conducting ions, their mobility and extent of aggregation. Conductivity and mobility show Vogel temperature dependence and increase with PEG content; even though PTMG ionomers have lower Tg. Conducting ion densities show Arrhenius temperature dependence and are nearly identical for polymers containing PEG. SAXS confirms the extent of aggregation and temperature response from dielectric results, and exposes phase separation as PTMG content is increased. The tradeoff between ion-solvation and low Tg in this study provides fundamental understanding of ionic aggregation and ion transport in polymer electrolytes.

  4. Kinetics of low frequency sonodegradation of linear alkylbenzene sulfonate solutions.

    PubMed

    Abu-Hassan, Mohd A; Kim, Jung K; Metcalfe, Ian S; Mantzavinos, Dionissios

    2006-02-01

    The decomposition of sodium dodecylbenzene sulfonate (SDBS) in water by means of ultrasound irradiation at 20kHz was investigated. Experiments were conducted at surfactant concentrations of 175, 260 and 350 mg l(-1), liquid volumes of 120, 170 and 220 ml, temperatures of 20, 30 and 45 degrees C and applied power of 40, 80 and 125 W. The extent of degradation was followed monitoring substrate and organic carbon concentrations, while hydrogen peroxide concentration was also measured; the latter is a product of water sonolysis due to hydroxyl radical recombination. 80% SDBS conversion was achieved after 120 min of sonication at 125 W and 30 degrees C; nonetheless, SDBS and its degradation intermediates proved difficult to oxidise as only about 20-25% of the initial carbon content was transformed to carbon dioxide. At the initial stages of the reaction, degradation rate appears to be only weakly dependent on the substrate concentration with the rate increasing from 3.1 to 4 mg l(-1)min(-1) with increasing concentration from 175 to 350 mg l(-1). Degradation appears to occur at the bubble-liquid interface through hydroxyl radical-mediated reactions whose role was established by performing experiments in the presence of radical scavengers, namely potassium bromide and sodium benzoate. Degradation rates increased with increasing power and decreasing temperature and volume. PMID:15975625

  5. Tissue Distribution Of Chloroaluminium Sulfonated Phthalocyanine In Dogs

    NASA Astrophysics Data System (ADS)

    M. M.; H. C.; Newman

    1989-06-01

    Chloroaluminum sulfonated phthalocyanine (A1PCS) was administered intravenously to clinically normal dogs, and A1PCS levels were determined in tissues using a sensitive assay. A1PCS accumulated to high levels in liver, spleen, bone marrow, kidney, and lung. These tissue levels confirm previous determinations in mice and rats. Only a small amount of dye was retained in skin and very small amounts in muscle and brain. A1PCS was cleared from the blood within 24 h, and excreted primarily by urine. Serum clearance was faster in males than in females. There were also significant tissue distribution differences between the genders, particularly during the first 12 h. The low levels of A1PCS in skin suggest that cutaneous photosensitivity and toxic skin reactions using this photosensitizer in photodynamic therapy of cancer may be eliminated. The difference in tissue distribution between genders is not only intriguing, but indicates that the optimal time window for treatment of various tissue sites may vary by gender.

  6. Partitioning characteristics of perfluorooctane sulfonate between water and foods.

    PubMed

    Xiao, Feng; Simcik, Matt F; Gulliver, John S

    2012-01-01

    As a persistent, bioaccumulative, and toxic organic pollutant, perfluorooctane sulfonate (PFOS) has been found ubiquitously in the environment, including in tap water. For the first time, we studied PFOS sorption from water to foods (nine commonly consumed vegetables, three meats, and cereals) at two temperatures to estimate the daily intake of PFOS attributable to cooking and food preparation. The values of the food water-distribution coefficient (KF/W, l/kg) of PFOS ranged from 7 to 19 l/kg for most vegetables and from 19 to 38 l/kg for meats. Celery exhibited the highest affinity toward PFOS (KF/W=39.8±3.4 l/kg), whereas onions showed the lowest affinity toward PFOS (KF/W=1.1±0.4 l/kg). Adding table salt (sodium chloride) greatly increased PFOS sorption in most foods, except for celery and meats. The results indicate that human exposure to PFOS could result from the sorption of PFOS from water to food during food preparation, especially when using table salt. The average daily intake of PFOS through this route was estimated. Furthermore, raw and unprocessed foods (vegetables, meats, and cereals) bought from farmers' markets and grocery stores were basically free of PFOS and other long-chain perfluoroalkyl acids. PMID:21597984

  7. Sulfonated nanocellulose for the efficient dispersive micro solid-phase extraction and determination of silver nanoparticles in food products.

    PubMed

    Ruiz-Palomero, Celia; Soriano, M Laura; Valcárcel, Miguel

    2016-01-01

    This paper reports a simple approach to Analytical Nanoscience and Nanotechnology (AN&N) that integrates the nanotool, sulfonated nanocellulose (s-NC), and nanoanalyte, silver nanoparticles (AgNPs), in the same analytical process by using an efficient, environmentally friendly dispersive micro solid-phase extraction (D-μSPE) capillary electrophoresis (CE) method with s-NC as sorbent material. Introducing negatively charged sulfate groups onto the surface of cellulose enhances its surface chemistry and enables the extraction and preconcentration of AgNPs of variable diameter (10, 20 and 60nm) and shell composition (citrate and polyvinylpyrrolidone coatings) from complex matrices into a cationic surfactant. In this way, AgNPs of diverse nature were successfully extracted onto the s-NC sorbent and then desorbed into an aqueous solution containing thiotic acid (TA) prior to CE without the need for any labor-intensive cleanup. The ensuing eco-friendly D-μSPE method exhibited a linear response to AgNPs with a limit of detection (LOD) of 20μg/L. Its ability to specifically recognize AgNPs of different sizes was checked in orange juice and mussels, which afforded recoveries of 70.9-108.4%. The repeatability of the method at the limit of quantitation (LOQ) level was 5.6%. Based on the results, sulfonated nanocellulose provides an efficient, cost-effective analytical nanotool for the extraction of AgNPs from food products. PMID:26116191

  8. Ag (I)-based 2D metal frameworks with helical structures decorated by the homochiral camphor-10-sulfonic acid

    NASA Astrophysics Data System (ADS)

    Guo, Peng; Wang, Jing; Wang, Jun; Pan, Daocheng; Xu, Guohai

    2010-12-01

    Two two-dimension homochiral Ag (I) metal frameworks constructed from enantiopure camphor-10-sulfonic acid and hexamethylenetetramine have been synthesized at the room temperature. These two complexes with (6, 3) topology decorated by the homochiral camphor-10-sulfonic acid possess the unique helical structures. The result of Circular Dichroism (CD) spectroscopy confirms that the bulk materials are homochiral and also indicates the handedness of the single crystals can be controlled by the chirality of the camphor-10-sulfonic acid.

  9. The Efficacy and Underlying Mechanism of Sulfone Derivatives Containing 1,3,4-oxadiazole on Citrus Canker.

    PubMed

    Li, Pei; Ma, Yuhua; Zhou, Junliang; Luo, Hui; Yan, Jiawen; Mao, Yongya; Wang, Zhuang

    2015-01-01

    The objectives of the current study were to isolate and identify the pathogen responsible for citrus canker and investigate the efficacy of sulfone derivatives containing 1,3,4-oxadiazole moiety on controlling citrus canker caused by Xanthomonas citri subsp. citri (Xcc) under in vitro and field conditions. In an in vitro study, we tested eight sulfone derivatives against Xcc and the results demonstrated that compound 3 exhibited the best antibacterial activity against Xcc, with a half-maximal effective concentration (EC50) value of 1.23 μg/mL, which was even better than those of commercial bactericides Kocide 3000 (58.21 μg/mL) and Thiodiazole copper (77.04 μg/mL), respectively. Meanwhile, under field experiments, compound 3 treatments demonstrated the highest ability to reduce the disease of citrus canker in leaves and fruits in two different places relative to an untreated control as well as the commercial bactericides Kocide 3000 and Thiodiazole copper. Meanwhile, compound 3 could stimulate the increase in peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL) activities in the navel orange leaves, causing marked enhancement of plant resistance against citrus canker. Moreover, compound 3 could damage the cell membranes, destruct the biofilm formation, inhibit the production of extracellular polysaccharide (EPS), and affect the cell membrane permeability to restrain the growth of the bacteria. PMID:26247929

  10. Iron-Catalyzed Cross-Coupling of Unactivated, Secondary Alkyl Thio Ethers and Sulfones with Aryl Grignard Reagents

    PubMed Central

    Denmark, Scott E.; Cresswell, Alexander J.

    2013-01-01

    The first systematic investigation of unactivated aliphatic sulfur compounds as electrophiles in transition metal-catalyzed cross-coupling are described. Initial studies focused on discerning the structural and electronic features of the organosulfur substrate which enable the challenging oxidative addition to the C(sp3)–S bond. Through extensive optimization efforts, an Fe(acac)3-catalyzed cross-coupling of unactivated alkyl aryl thio ethers with aryl Grignard reagents was realized, in which a nitrogen “directing group” on the S-aryl moiety of the thio ether served a critical role in facilitating the oxidative addition step. In addition, alkyl phenyl sulfones were found to be effective electrophiles in the Fe(acac)3-catalyzed cross-coupling with aryl Grignard reagents. For the latter class of electrophile, a thorough assessment of the various reaction parameters revealed a dramatic enhancement in reaction efficiency with an excess of TMEDA (8.0 equiv). The optimized reaction protocol was used to evaluate the scope of the method with respect to both the organomagnesium nucleophile and sulfone electrophile. PMID:24256193

  11. Friedel–Crafts Crosslinked Highly Sulfonated Polyether Ether Ketone (SPEEK) Membranes for a Vanadium/Air Redox Flow Battery

    PubMed Central

    Merle, Géraldine; Ioana, Filipoi Carmen; Demco, Dan Eugen; Saakes, Michel; Hosseiny, Seyed Schwan

    2014-01-01

    Highly conductive and low vanadium permeable crosslinked sulfonated poly(ether ether ketone) (cSPEEK) membranes were prepared by electrophilic aromatic substitution for a Vanadium/Air Redox Flow Battery (Vanadium/Air-RFB) application. Membranes were synthesized from ethanol solution and crosslinked under different temperatures with 1,4-benzenedimethanol and ZnCl2 via the Friedel–Crafts crosslinking route. The crosslinking mechanism under different temperatures indicated two crosslinking pathways: (a) crosslinking on the sulfonic acid groups; and (b) crosslinking on the backbone. It was observed that membranes crosslinked at a temperature of 150 °C lead to low proton conductive membranes, whereas an increase in crosslinking temperature and time would lead to high proton conductive membranes. High temperature crosslinking also resulted in an increase in anisotropy and water diffusion. Furthermore, the membranes were investigated for a Vanadium/Air Redox Flow Battery application. Membranes crosslinked at 200 °C for 30 min with a molar ratio between 2:1 (mol repeat unit:mol benzenedimethanol) showed a proton conductivity of 27.9 mS/cm and a 100 times lower VO2+ crossover compared to Nafion. PMID:24957118

  12. Shifting from hydrogen bond network to π-π stacking: a key mechanism for reversible thermochromic sulfonated poly(ether ether ketone).

    PubMed

    Jarumaneeroj, Chatchai; Tashiro, Kohji; Chirachanchai, Suwabun

    2014-08-01

    Sulfonated poly(ether ether ketone) (SPEEK) thin film performs reversible thermochromic property by developing the color to be yellowish at the temperature above 190 °C. The detailed analyses based on temperature-dependent techniques suggest the thermal treatment inducing the shifting of the hydrogen bond network between the sulfonated group and the hydrated water molecules to the π-π stacking among aromatic rings in SPEEK chains. Although it is general that the polymer chain packing is unfavorable at high temperature, the present work shows a good example that when the polymer chains can form specific molecular interaction, such as π-π stacking, even in harsh thermal treatment, a rearrangement will effectively occur, which leads to an external stimuli-responsive property. PMID:24942891

  13. Imidazolium Sulfonates as Environmental-Friendly Catalytic Systems for the Synthesis of Biologically Active 2-Amino-4H-chromenes: Mechanistic Insights.

    PubMed

    Velasco, Jacinto; Pérez-Mayoral, Elena; Calvino-Casilda, Vanesa; López-Peinado, Antonio J; Bañares, Miguel A; Soriano, Elena

    2015-09-10

    Ionic Liquids (ILs) are valuable reaction media extremely useful in industrial sustainable organic synthesis. We describe here the study on the multicomponent reaction (MCR) between salicylaldehyde (2) and ethyl cyanoacetate (3), catalyzed by imidazolium sulfonates, to form chromenes 1, a class of heterocyclic scaffolds exhibiting relevant biological activity. We have clarified the reaction mechanism by combining the experimental results with computational studies. The results reported herein suggest that both the imidazolium core and the sulfonate anions in the selected ILs are involved in the reaction course acting as hydrogen bond donors and acceptors, respectively. Contrarily to the most widely accepted mechanism through initial Knoevenagel condensation, the most favorable reaction pathway consists of an aldolic reaction between reagents followed by heterocyclization, subsequent dehydration, and, finally, the Michael addition of the second molecule of ethyl cyanoacetate (3) to yield the chromenes 1. PMID:26301460

  14. Grafting titanium nitride surfaces with sodium styrene sulfonate thin films.

    PubMed

    Zorn, Gilad; Migonney, Véronique; Castner, David G

    2014-09-01

    The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ∼1.5 and ∼1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260 ± 70 ng/cm(2). PMID:25280842

  15. Grafting titanium nitride surfaces with sodium styrene sulfonate thin films

    PubMed Central

    Zorn, Gilad; Migonney, Véronique; Castner, David G.

    2014-01-01

    The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ∼1.5 and ∼1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260 ± 70 ng/cm2. PMID:25280842

  16. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination from textiles.

    PubMed

    Supreeyasunthorn, Phenpimuk; Boontanon, Suwanna K; Boontanon, Narin

    2016-05-11

    The goals of this study were to determine the concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in textiles and to determine PFOS and PFOA contamination in textile washing water. Quantification analysis was performed by high performance liquid chromatography coupled with tandem mass spectrometry. Analysis of 32 textile samples by methanol extraction revealed that the average concentrations of PFOS and PFOA were 0.18 µg m(-2) (0.02 to 0.61 µg m(-2)) and 2.74 µg m(-2) (0.31 to 14.14 µg m(-2)), respectively. Although the average concentration of PFOS found in textile samples was below European Union (EU) Commission regulations (<1 µg m(-2)), the average concentration of PFOA was 2.74 µg m(-2), and 68.75% of textile samples had PFOA concentrations exceeding 1 µg m(-2). Thus, based on these results, the concentration of PFOA in products should also be regulated. Experiments on PFOS and PFOA leaching into washing water were conducted. The maximum concentrations of PFOS and PFOA were measured after the first washing; the concentrations gradually decreased with each subsequent washing. PFOS and PFOA migrated from textiles and were released into the environment, with disappearance percentages of 29.8% for PFOS and 99% for PFOA. The data presented in this study showed that textiles could be a significant direct and indirect source of PFOS and PFOA exposure for both humans and the environment. PMID:26864911

  17. A sulfonic-azobenzene-grafted silica amphiphilic material: a versatile stationary phase for mixed-mode chromatography.

    PubMed

    Qiu, Hongdeng; Zhang, Mingliang; Gu, Tongnian; Takafuji, Makoto; Ihara, Hirotaka

    2013-12-23

    A novel sulfonic-azobenzene-functionalized amphiphilic silica material was synthesized through the preparation of a new sulfonic azobenzene monomer and its grafting on mercaptopropyl-modified silica by a surface-initiated radical chain-transfer reaction. The synthesis was confirmed by infrared spectra, elemental analysis, and thermogravimetric analysis. This new material was successfully applied as a new kind of mixed-mode stationary phase in liquid chromatography. This allows an exceptionally flexible adjustment of retention and selectivity by tuning the experimental conditions. The distinct separation mechanisms were outlined by selected examples of chromatographic separations in the different modes. In reversed-phase liquid chromatography, this new stationary phase presented specific chromatographic performance when evaluated using a Tanaka test mixture. Seven dinitro aromatic isomers, four steroids, and seven flavonoids were separated successfully in simple reversed-phase mode. This stationary phase can also be used in hydrophilic interaction chromatography because of the existing polar functional groups; for this, nucleosides and their bases were used as a test mixture. Interestingly, the same nucleosides and bases can also be separated in per aqueous liquid chromatography using the same stationary phase. Three ginsenosides including Rg1, Re, and Rb1 were successfully separated in hydrophilic mode. There is the potential for more applications to benefit from this useful column. PMID:24353082

  18. Synthesis Of [2h, 13c]M [2h2m 13c], And [2h3,, 13c] Methyl Aryl Sulfones And Sulfoxides

    DOEpatents

    Martinez, Rodolfo A.; Alvarez, Marc A.; Silks, III, Louis A.; Unkefer, Clifford J.; Schmidt, Jurgen G.

    2004-07-20

    The present invention is directed to labeled compounds, [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfones and [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfoxides, wherein the .sup.13 C methyl group attached to the sulfur of the sulfone or sulfoxide includes exactly one, two or three deuterium atoms and the aryl group is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently, hydrogen, a C.sub.1 -C.sub.4 lower alkyl, a halogen, an amino group from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each a C.sub.1 -C.sub.4 lower alkyl, a phenyl, or an alkoxy group. The present invention is also directed to processes of preparing methyl aryl sulfones and methyl aryl sulfoxides.

  19. Crystal structures of three N-(aryl­sulfon­yl)-4-fluoro­benzamides

    PubMed Central

    Suchetan, P. A.; Naveen, S.; Lokanath, N. K.; Srivishnu, K. S.; Supriya, G. M.; Lakshmikantha, H. N.

    2016-01-01

    The crystal structures of three N-aryl­sulfonyl-4-fluoro­benzamides, namely 4-fluoro-N-(2-methyl­phenyl­sulfon­yl)benzamide, C14H12FNO3S, (I), N-(2-chloro­phenyl­sulfon­yl)-4-fluorobenzamide, C13H9ClFNO3S, (II), and N-(4-chloro­phenyl­sulfon­yl)-4-fluoro­benzamide monohydrate, C13H9ClFNO3S·H2O, (III), are described and compared with related structures. The asymmetric unit of (I) contains two independent mol­ecules (A and B), while that of (II) contains just one mol­ecule, and that of (III) contains a mol­ecule of water in addition to one main mol­ecule. The dihedral angle between the benzene rings is 82.83 (11)° in mol­ecule A and 85.01 (10)° in mol­ecule B of (I), compared to 89.91 (10)° in (II) and 81.82 (11)° in (III). The crystal structure of (I) features strong N—H⋯O hydrogen bonds between the A and B mol­ecules, resulting in an R 4 4(16) tetra­meric unit. These tetra­meric units are connected into sheets in the bc plane by various C—H⋯O inter­actions, and adjacent sheets are further inter­linked via C—H⋯πar­yl inter­actions, forming a three-dimensional architecture. The crystal structure is further stabilized by πar­yl–πar­yl and S=O⋯πar­yl inter­actions. In the crystal of (II), mol­ecules are connected into R 2 2(8) and R 2 2(14) dimers via N—H⋯O hydrogen bonds and C—H⋯O inter­actions, respectively; the dimers are further inter­connected via a weak C=O⋯πar­yl inter­action, leading to the formation of chains along [1-10]. In the crystal of (III), N—H⋯O and O—H⋯O hydrogen bonds involving both the main mol­ecule and the solvent water mol­ecule results in the formation of sheets parallel to the bc plane. The sheets are further connected by C—H⋯O inter­actions and weak C—Cl⋯πar­yl, C—F⋯πar­yl and S=O⋯πar­yl inter­actions, forming a three-dimensional architecture. PMID:27375892

  20. Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts.

    PubMed

    Siddiki, S M A Hakim; Touchy, Abeda Sultana; Kon, Kenichi; Shimizu, Ken-Ichi

    2016-04-18

    Carbon-supported Pt nanoparticles (Pt/C) were found to be effective heterogeneous catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant-free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar H2, the same reaction system was effective for the transformation of alcohol OH groups to alkyl groups. Structural and mechanistic studies of the terminal olefination system suggested that Pt(0) sites on the Pt metal particles are responsible for the rate-limiting dehydrogenation of alcohols and that KOtBu may deprotonate the sulfone reagent. The Pt/C catalyst was reusable after the olefination, and this method showed a higher turnover number (TON) and a wider substrate scope than previously reported methods, which demonstrates the high catalytic efficiency of the present method. PMID:26928740

  1. Copoly(arlene ether)s containing pendant sulfonic acid groups as proton exchange membrane

    SciTech Connect

    Kim, Yu Seung; Kim, Dae Sik; Robertson, Gilles; Guiver, Michael

    2008-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The P AE and PAEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2-phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. The sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sP AE and sP AEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (DS) of 1.0 had high ion exchange capacities (IEC{sub v}(wet) (volume-based, wet state)) of 1.77 and 2.55 meq./cm{sup 3}, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5-51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the area of outstanding properties in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based). Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  2. Thyroid disruption effects of environmental level perfluorooctane sulfonates (PFOS) in Xenopus laevis.

    PubMed

    Cheng, Yan; Cui, Yuan; Chen, Hui-ming; Xie, Wen-ping

    2011-11-01

    Perfluorooctane sulfonate (PFOS), one of the emerging persistent organic pollutants (POPs), has caused growing international concern especially related to the potential disruption in the development and function of thyroid system. Xenopus laevis is an amphibian species widely used as a suitable amphibian model for thyroid disruption research. To study the thyroid disruption effects related to PFOS exposure at environmental low levels, X. laevis tadpoles were exposed to 0.1, 1, 10 and 100 μg/l PFOS in water respectively from stage 46/47 to stage 62. The results showed that the time to metamorphosis (presented by forelimb emergence, FLE) did not significantly change with PFOS exposure, but exhibited an increasing trend (except for 10 μg/l exposure). Partial colloid depletion was observed for PFOS exposure, but no significant histological abnormality was observed in treatment groups. In addition, PFOS exposure resulted in up-regulation of thyroid hormone-regulated genes-thyroid receptor beta A (TRβA), basic transcription element-binding protein (BTEB) and type II deiodinase (DI2) mRNA expression, presented as an inverted U-shaped dose response pattern. However, the mRNA expression of type III deiodinase (DI3) remained unaffected compared with the control. These results demonstrated that PFOS might disrupt the thyroid system in X. laevis tadpoles regarding FLE changes and regulation alternation of thyroid hormone-regulated genes. Our study has raised new concerns for possible thyroid disruption of PFOS in amphibians at environmental relevant levels. PMID:21809121

  3. Sodium dodecyl benzene sulfonate-assisted synthesis through a hydrothermal reaction

    SciTech Connect

    Sobhani, Azam; Salavati-Niasari, Masoud

    2012-08-15

    Graphical abstract: Reaction of a SeCl{sub 4} aqueous solution with a NiCl{sub 2}·6H{sub 2}O aqueous solution in presence of sodium dodecyl benzene sulfonate (SDBS) as capping agent and hydrazine (N{sub 2}H{sub 4}·H{sub 2}O) as reductant, produces nanosized nickel selenide through a hydrothermal method. The effect of temperature, reaction time and amounts of reductant on the morphology, particle sizes of NiSe nanostructures has been investigated. Highlights: ► NiSe nanostructures were synthesized by hydrothermal method. ► A novel Se source was used to synthesize NiSe. ► SDBS as capping agent plays a crucial role on the morphology of products. ► A mixture of Ni{sub 3}Se{sub 2} and NiSe was prepared in the presence of 2 ml hydrazine. ► A pure phase of NiSe was prepared in the presence of 4 or 6 ml hydrazine. -- Abstract: The effects of the anionic surfactant on the morphology, size and crystallization of NiSe precipitated from NiCl{sub 2}·6H{sub 2}O and SeCl{sub 4} in presence of hydrazine (N{sub 2}H{sub 4}·H{sub 2}O) as reductant were investigated. The products have been successfully synthesized in presence of sodium dodecyl benzene sulfonate (SDBS) as surfactant via an improved hydrothermal route. A variety of synthesis parameters, such as reaction time and temperature, capping agent and amount of reducing agent have a significant effect on the particle size, phase purity and morphology of the obtained products. The sample size became bigger with decreasing reaction temperature and increasing reaction time. In the presence of 2 ml hydrazine, the samples were found to be the mixture of Ni{sub 3}Se{sub 2} and NiSe. With increasing the reaction time and amount of hydrazine a pure phase of hexagonal NiSe was obtained. X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) images indicate phase, particle size and morphology of the products. Chemical composition and purity of the products were

  4. Sulfone-stabilized carbanions for the reversible covalent capture of a posttranslationally-generated cysteine oxoform found in protein tyrosine phosphatase 1B (PTP1B).

    PubMed

    Parsons, Zachary D; Ruddraraju, Kasi Viswanatharaju; Santo, Nicholas; Gates, Kent S

    2016-06-15

    Redox regulation of protein tyrosine phosphatase 1B (PTP1B) involves oxidative conversion of the active site cysteine thiolate into an electrophilic sulfenyl amide residue. Reduction of the sulfenyl amide by biological thiols regenerates the native cysteine residue. Here we explored fundamental chemical reactions that may enable covalent capture of the sulfenyl amide residue in oxidized PTP1B. Various sulfone-containing carbon acids were found to react readily with a model peptide sulfenyl amide via attack of the sulfonyl carbanion on the electrophilic sulfur center in the sulfenyl amide. Both the products and the rates of these reactions were characterized. The results suggest that capture of a peptide sulfenyl amide residue by sulfone-stabilized carbanions can slow, but not completely prevent, thiol-mediated generation of the corresponding cysteine-containing peptide. Sulfone-containing carbon acids may be useful components in the construction of agents that knock down PTP1B activity in cells via transient covalent capture of the sulfenyl amide oxoform generated during insulin signaling processes. PMID:27132865

  5. High proton-conducting organic/inorganic nanocomposite films based on sulfonated polystyrene-block-poly(ethyl-ran-propylene)-block-polystyrene and silica nanoparticles.

    PubMed

    Jang, Suk-Yong; Han, Sien-Ho

    2013-12-01

    Sulfonated polystyrene-block-poly(ethyl-ran-propylene)-block-polystyrene (S-polySEPS) was prepared by sulfonation at the phenyl groups of the polystyrene-block-poly(ethyl-ran-propylene)-block-polystyrene (polySEPS) containing 65% styrene groups for proton exchange membrane. High proton-conducting S-polySEPS/silica nanocomposite films were produced by direct-mixing of nanosilica particles with the S-polySEPS copolymer. The TEM image of the S-polySEPS/silica nanocomposite films showed that the silica particles were very-well dispersed within the S-polySEPS matrix. Also, the XRD patterns showed the presence of the nano-scaled silica particles. Moreover, the nano-scaled silica particles played an important role in the prepared organic/inorganic nanocomposite properties such as proton conductivity, thermal stability, water content and ion exchange capacity (IEC). The S-polySEPS/silica 1 wt% (1.41 x 10(-1) S/cm) and 2 wt% (9.9 x 10(-2) S/cm) nanocomposite films had higher proton conductivity than Nafion 117 (9.8 x 10(-2) S/cm) at the temperature of 90 degrees C. The FT-IR analysis was used to verify the sulfonation of the S-polySEPS copolymer. The TGA analysis was carried out to investigate the thermal stability of the S-polySEPS/silica nanocomposite films. PMID:24266146

  6. Non-classical azoreductase secretion in Clostridium perfringens in response to sulfonated azo dye exposure.

    PubMed

    Morrison, Jessica M; John, Gilbert H

    2015-08-01

    Clostridium perfringens, a strictly anaerobic microorganism and inhabitant of the human intestine, has been shown to produce an azoreductase enzyme (AzoC), an NADH-dependent flavin oxidoreductase. This enzyme reduces azo dyes into aromatic amines, which can be carcinogenic. A significant amount of work has been completed on the activity of AzoC. Despite this, much is still unknown, including whether azoreduction of these dyes occurs intracellularly or extracellulary. A physiological study of C. perfringens involving the effect of azo dye exposure was completed to answer this question. Through exposure studies, azo dyes were found to cause cytoplasmic protein release, including AzoC, from C. perfringens in dividing and non-dividing cells. Sulfonation (negative charge) of azo dyes proved to be the key to facilitating protein release of AzoC and was found to be azo-dye-concentration-dependent. Additionally, AzoC was found to localize to the Gram-positive periplasmic region. Using a ΔazoC knockout mutant, the presence of additional azoreductases in C. perfringens was suggested. These results support the notion that the azoreduction of these dyes may occur extracellularly for the commensal C. perfringens in the intestine. PMID:25881497

  7. Crystal structure of potassium (1S)-d-lyxit-1-yl­sulfonate monohydrate

    PubMed Central

    Haines, Alan H.; Hughes, David L.

    2015-01-01

    The title compound, K+·C5H11O8S−·H2O [systematic name: potassium (1S,2S,3S,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate monohydrate], formed by reaction of d-lyxose with potassium hydrogen sulfite in water, crystallizes as colourless square prisms. The anion has an open-chain structure in which the S atom, the C atoms of the sugar chain and the oxygen atom of the hy­droxy­methyl group form an essentially all-trans chain with the corresponding torsion angles lying between 178.61 (12) and 157.75 (10)°. A three-dimensional bonding network exists in the crystal structure involving coordination of two crystallographically independent potassium ions by O atoms (one cation being hexa- and the other octa-coordinate, with each lying on a twofold rotation axis), and extensive inter­molecular O—H⋯O hydrogen bonding. PMID:26396774

  8. Crystal structure of potassium (1S)-d-lyxit-1-yl-sulfonate monohydrate.

    PubMed

    Haines, Alan H; Hughes, David L

    2015-08-01

    The title compound, K(+)·C5H11O8S(-)·H2O [systematic name: potassium (1S,2S,3S,4R)-1,2,3,4,5-penta-hydroxy-pentane-1-sulfonate monohydrate], formed by reaction of d-lyxose with potassium hydrogen sulfite in water, crystallizes as colourless square prisms. The anion has an open-chain structure in which the S atom, the C atoms of the sugar chain and the oxygen atom of the hy-droxy-methyl group form an essentially all-trans chain with the corresponding torsion angles lying between 178.61 (12) and 157.75 (10)°. A three-dimensional bonding network exists in the crystal structure involving coordination of two crystallographically independent potassium ions by O atoms (one cation being hexa- and the other octa-coordinate, with each lying on a twofold rotation axis), and extensive inter-molecular O-H⋯O hydrogen bonding. PMID:26396774

  9. Aqueous solution deposition kinetics of iron oxyhydroxide on sulfonic acid terminated self-assembled monolayers

    SciTech Connect

    Rieke, P.C.; Marsh, B.D.; Wood, L.L.; Tarasevich, B.J.; Liu, J.; Song, L.; Fryxell, G.E. )

    1995-01-01

    The deposition kinetics of iron oxyhydroxide on sulfonic acid terminated self-assembled monolayers were studied. The thin films of FeOOH were formed on the substrates by thermal hydrolysis of millimolar aqueous solutions of Fe(NO[sub 3])[sub 3] at a pH of approximately 2.0. The thickness of the films was measured ellipsometrically at various times. Both Fe(NO[sub 3])[sub 3] and HNO[sub 3] concentrations were independently varied to provide varying degrees of solution supersaturation. Depending on these concentrations, an induction time was observed before film growth commenced. The correlation between supersaturation and induction time was modeled using classical nucleation theory. Very good agreement was observed regardless of whether supersaturation was varied via the concentration of Fe(NO[sub 3])[sub 3] or HNO[sub 3]. From these results an interfacial free energy for nucleation of 148 mJ/m[sup 2] was calculated. The critical nucleus species was identified as a tetrameric iron species by considering the order of nucleation. 49 refs., 11 figs., 1 tab.

  10. Sodium polyanethol sulfonate (SPS) falsifies protein staining and quantification and how to solve this problem.

    PubMed

    Prax, Marcel; Vatani Shahmirzadi, Shideh; Götz, Friedrich

    2015-11-01

    Sodium polyanethol sulfonate (SPS) is an anionic detergent with a broad range of activities and applications. While studying the excretion of cytoplasmic proteins in Staphylococcus aureus SPS was used as cell lysis inhibitor. When investigating the protein pattern of culture supernatants from cells grown in the absence or presence of SPS by Coomassie blue stained polyacrylamide gel the amount of protein bands was significantly decreased in the presence of SPS, suggesting that this effect was due to inhibition of cell lysis. However, various control studies showed that the apparent decreased protein secretion was an artifact due to the interference of SPS with Coomassie blue- and silver-staining. The only alternative method that was uninfluenced by SPS was imidazole-SDS-zinc staining. This is the method of choice particularly when protein interfering compounds are present in the extracts. For protein quantification in liquid samples the bicinchoninic acid (BCA) assay appeared to be the method of choice in the presence of SPS. The assay is based on neutral peptide bonds and is therefore rather insensitive to interfering compounds. This study shows that SPS and most likely also related detergents might falsify conventional protein staining and quantification methods. PMID:26456688

  11. Sortase inhibitor phenyl vinyl sulfone inhibits Renibacterium salmoninarum adherence and invasion of host cells.

    PubMed

    Sudheesh, Ponnerassery S; Crane, Samuel; Cain, Kenneth D; Strom, Mark S

    2007-12-13

    Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fishes, is a Gram-positive diplococcobacillus belonging to the family Micrococcaceae. Analysis of the genome sequence of the bacterium demonstrated the presence of a sortase homolog (srtD), a gene specifying an enzyme found in Gram-positive bacteria and required for covalent anchoring of cell surface proteins. Interference of sortase activity is being examined as a target for therapeutic prevention of infection by several pathogenic Gram-positive bacterial species. In silico analysis identified 8 open reading frames containing sortase recognition motifs, suggesting these proteins are translocated to the bacterial cell wall. The sortase and potential sortase substrate genes are transcribed in R. salmoninarum, suggesting they encode functional proteins. Treatment of R. salmoninarum with phenyl vinyl sulfone (PVS) significantly reduced bacterial adherence to Chinook salmon fibronectin. In addition, the ability of the PVS-treated bacteria to adhere to Chinook salmon embryo cells (CHSE-214) in vitro was dramatically reduced compared to that of untreated bacteria. More importantly, PVS-treated bacteria were unable to invade and replicate within CHSE-214 cells (demonstrated by an intracellular growth assay and by light microscopy). When treated with PVS, R. salmoninarum was not cytopathic to CHSE-214 cells, whereas untreated bacteria produced cytopathology within a few days. These findings clearly show that PVS, a small molecule drug and a known sortase inhibitor, can interfere with the ability of R. salmoninarum to adhere and colonize fish cells, with a corresponding decrease in virulence. PMID:18286808

  12. Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Structural evolution with hydration and heating

    SciTech Connect

    Sodeye, Akinbode; Huang, Tianzi; Gido, Samuel; Mays, Jimmy

    2011-01-01

    Small-angle neutron scattering (SANS) and ultra-small-angle X-ray scattering (USAXS) have been used to study the structural changes in fluorinated polyisoprene/sulfonated polystyrene (FISS) diblock copolymers as they evolved from the dry state to the water swollen state. A dilation of the nanometer-scale hydrophilic domains has been observed as hydration increased, with greater dilation occurring in the more highly sulfonated samples or upon hydration at higher temperatures. Furthermore, a decrease in the order in these phase separated structures is observed upon swelling. The glass transition temperatures of the fluorinated blocks have been observed to decrease upon hydration of these materials, and at the highest hydration levels, differential scanning calorimetry (DSC) has shown the presence of tightly bound water. A precipitous drop in the mechanical integrity of the 50% sulfonated materials is also observed upon exceeding the glass transition temperature (Tg), as measured by dynamic mechanical analysis (DMA).

  13. Synthesis of porous sulfonated carbon as a potential adsorbent for phenol wastewater.

    PubMed

    Prabhu, Azhagapillai; Al Shoaibi, Ahmed; Srinivasakannan, C

    2015-01-01

    The work reports a facile synthesis procedure for preparation of porous sulfonated carbons and its suitability for adsorption of phenol. The sulfonated carbon was synthesized utilizing a simplified, single-step, shorter duration process by sulfonation, dehydration and carbonization of sucrose in sulfuric acid and tetraethylorthosilicate. The surface and internal structures of the adsorbents were characterized utilizing various characterization techniques to understand the porous nature and surface functional groups of the porous matrix. Adsorption capacity was found to be highest for the sample heat treated at 600 °C, with the maximum adsorption capacity of 440 mg/g at 30 °C. The adsorption isotherms were tested with the Freundlich and Langmuir adsorption isotherms models to identify the appropriate adsorption mechanism. PMID:26524451

  14. QENS investigation of proton confined motions in hydrated perfluorinated sulfonic membranes and self-assembled surfactants

    NASA Astrophysics Data System (ADS)

    Berrod, Quentin; Lyonnard, Sandrine; Guillermo, Armel; Ollivier, Jacques; Frick, Bernhard; Gébel, Gérard

    2015-01-01

    We report on QuasiElastic Neutron Scattering (QENS) investigations of the dynamics of protons and water molecules confined in nanostructured perfluorinated sulfonic acid (PFSA) materials, namely a commercial Aquivion membrane and the perfluorooctane sulfonic acid (PFOS) surfactant. The former is used as electrolyte in low-temperature fuel cells, while the latter forms mesomorphous self-assembled phases in water. The dynamics was investigated as a function of the hydration level, in a wide time range by combining time-of-flight and backscattering incoherent QENS experiments. Analysis of the quasielastic broadening revealed for both systems the existence of localized translational diffusive motions, fast rotational motions and slow hopping of protons in the vicinity of the sulfonic charges. The characteristic times and diffusion coefficients have been found to exhibit a very similar behaviour in both membrane and surfactant structures. Our study provides a comprehensive picture of the proton motion mechanisms and the dynamics of confined water in model and real PFSA nanostructures.

  15. Mechanoassisted Synthesis of Sulfonated Covalent Organic Frameworks with High Intrinsic Proton Conductivity.

    PubMed

    Peng, Yongwu; Xu, Guodong; Hu, Zhigang; Cheng, Youdong; Chi, Chenglong; Yuan, Daqiang; Cheng, Hansong; Zhao, Dan

    2016-07-20

    It is challenging to introduce pendent sulfonic acid groups into modularly built crystalline porous frameworks for intrinsic proton conduction. Herein, we report the mechanoassisted synthesis of two sulfonated covalent organic frameworks (COFs) possessing one-dimensional nanoporous channels decorated with pendent sulfonic acid groups. These COFs exhibit high intrinsic proton conductivity as high as 3.96 × 10(-2) S cm(-1) with long-term stability at ambient temperature and 97% relative humidity (RH). In addition, they were blended with nonconductive polyvinylidene fluoride (PVDF) affording a series of mixed-matrix membranes (MMMs) with proton conductivity up to 1.58 × 10(-2) S cm(-1) and low activation energy of 0.21 eV suggesting the Grotthuss mechanism for proton conduction. Our study has demonstrated the high intrinsic proton conductivity of COFs shedding lights on their wide applications in proton exchange membranes. PMID:27385672

  16. Direct AFM force measurements between air bubbles in aqueous monodisperse sodium poly(styrene sulfonate) solutions.

    PubMed

    Browne, Christine; Tabor, Rico F; Grieser, Franz; Dagastine, Raymond R

    2015-08-01

    Structural forces play an important role in the rheology, processing and stability of colloidal systems and complex fluids, with polyelectrolytes representing a key class of structuring colloids. Here, we explore the interactions between soft colloids, in the form of air bubbles, in solutions of monodisperse sodium poly(styrene sulfonate) as a model polyelectrolyte. It is found that by self-consistently modelling the force oscillations due to structuring of the polymer chains along with deformation of the bubbles, it is possible to precisely predict the interaction potential between approaching bubbles. In line with polyelectrolyte scaling theory, two distinct regimes of behaviour are seen, corresponding to dilute and semi-dilute polymer solutions. It is also seen that by blending monodisperse systems to give a bidisperse sample, the interaction forces between soft colloids can be controlled with a high degree of precision. At increasing bubble collision velocity, it is revealed that hydrodynamic flow overwhelms oscillatory structural interactions, showing the important disparity between equilibrium behaviour and dynamic interactions. PMID:25881266

  17. Rectal stenosis caused by foreign body reaction to sodium polystyrene sulfonate crystals (Kayexalate).

    PubMed

    Chatelain, Denis; Brevet, Marie; Manaouil, David; Yzet, Thierry; Regimbeau, Jean-Marc; Sevestre, Henri

    2007-06-01

    Sodium polystyrene sulfonate (SPS) (Kayexalate) is a cation-exchange resin used to treat hyperkaliema. Administered with sorbitol, it usually has minor adverse effects, but it may cause colonic or intestinal necrosis in uremic patients. We report an unusual case of rectal stenosis due to SPS crystals in a 46-year-old man. The patient had been involved in a car accident with severe thoracic and abdominal trauma. During his hospitalization, he presented traumatic acute pancreatitis with ischemic colitis because of hypotension, and acute renal insufficiency treated by hemofiltration and Kayexalate administered by nasogastric tube without sorbitol. Left colon was resected and Hartmann's procedure was performed. Restoration of the colon continuity was performed 13 months later. The rectal lumen was narrowed with a thickened rectal wall. Microscopic examination revealed fibrosis of the submucosa containing numerous basophilic polygonal crystals surrounded by macrophages. This is the first case report of rectal stenosis caused by foreign body reaction to SPS crystals after ischemic colitis. PMID:17498597

  18. Surface initiated atom transfer radical polymerization grafting of sodium styrene sulfonate from titanium and silicon substrates

    PubMed Central

    Foster, Rami N.; Keefe, Andrew J.; Jiang, Shaoyi; Castner, David G.

    2013-01-01

    This study investigates the grafting of poly-sodium styrene sulfonate (pNaSS) from trichlorosilane/10-undecen-1-yl 2-bromo-2-methylpropionate functionalized Si and Ti substrates by atom transfer radical polymerization (ATRP). The composition, molecular structure, thickness, and topography of the grafted pNaSS films were characterized with x-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), variable angle spectroscopic ellipsometry (VASE), and atomic force microscopy (AFM), respectively. XPS and ToF-SIMS results were consistent with the successful grafting of a thick and uniform pNaSS film on both substrates. VASE and AFM scratch tests showed the films were between 25 and 49 nm thick on Si, and between 13 and 35 nm thick on Ti. AFM determined root-mean-square roughness values were ∼2 nm on both Si and Ti substrates. Therefore, ATRP grafting is capable of producing relatively smooth, thick, and chemically homogeneous pNaSS films on Si and Ti substrates. These films will be used in subsequent studies to test the hypothesis that pNaSS-grafted Ti implants preferentially adsorb certain plasma proteins in an orientation and conformation that modulates the foreign body response and promotes formation of new bone. PMID:24482558

  19. BPC-15 reduces trinitrobenzene sulfonic acid-induced colonic damage in rats.

    PubMed

    Veljaca, M; Lesch, C A; Pllana, R; Sanchez, B; Chan, K; Guglietta, A

    1995-01-01

    The effect of BPC-15 (Booly Protection Compound-15) was evaluated in a rat model of colonic injury. A single intracolonic administration of trinitrobenzene sulfonic acid (TNBS) dissolved in ethanol induces severe colonic damage, which is characterized by areas of necrosis surrounded by areas of acute inflammation. The damage is associated with high myeloperoxidase (MPO) activity, mainly as a reflection of neutrophilic infiltration into the damaged tissue. In this study, 1 hr before a single intracolonic administration of 50 mg/kg of TNBS in 50% ethanol, the animals were treated with one of the following doses of BPC-15: 0.0001, 0.001, 0.01, 0.1, 1 or 10 nmol/kg administered i.p. or with a dose of 10 nmol/kg administered intracolonically. The animals were sacrificed 3 days later and the extent of colonic necrosis and hyperemia was measured with an image analyzer. The i.p. administration of BPC-15 significantly reduced the extent of TNBS-induced colonic damage in a dose-dependent manner. This was associated with a statistically significant and dose-dependent reduction in colonic tissue MPO activity. At the dose tested (10 nmol/kg), intracolonic administration of BPC-15 did not significantly reduce either the extent of the colonic damage or the increase in MPO activity induced by TNBS. In conclusion, this study showed that i.p. administration of BPC-15 reduced TNBS-induced colonic damage in rats. PMID:7815358

  20. Evaluation of a laboratory-generated NOEC for linear alkylbenzene sulfonate in outdoor experimental streams

    SciTech Connect

    Fairchild, J.F.; Dwyer, F.J.; Point, T.W. la; Burch, S.A.; Ingersoll, C.G. . National Fisheries Contaminant Research Center)

    1993-10-01

    Laboratory and field studies were conducted with linear alkylbenzene sulfonate (LAS) to evaluate the use of the laboratory-generated NOECs for protecting aquatic organisms in outdoor experimental streams. Fathead minnows (Pimephales promelas) and freshwater amphipods (Hyalella azteca) were exposed in the laboratory to an environmentally realistic mixture of LAS for 7 d; fathead minnows were also exposed in a 28-d study. Calculated NOEC values based on survival and growth ranged from 0.3 to 0.9 mg/L for fathead minnows and from 0.6 to 1.4 mg/L for amphipods. Toxicity of LAS in 4-, 7-, and 28-d exposured of fathead minnows was similar because mortality occurred within the initial 24 h of exposure; mortality was more sensitive than growth as a chronic end point. The addition of 5% sewage effluent to well and stream water had little effect on the bioavailability of LAS; however, total organic carbon levels were low in all treatments. A 45-d exposure of three outdoor experimental streams to 0.36 mg/L LAS had no effects on survival of fathead minnows or amphipods, dynamics of benthic invertebrates, growth of periphyton, or processing of detrital leaves. Results indicated that the laboratory-generated NOEC for LAS was protective of experimental stream communities under the studied conditions.

  1. Chronic Exposure to Perfluorooctane Sulfonate Reduces Lifespan of Caenorhabditis elegans Through Insulin/IGF-1 Signaling.

    PubMed

    Xu, Tiantian; Li, Ping; Wu, Siyu; Li, Dan; Wu, Jingxuan; Raley-Susman, Kathleen M; He, Defu

    2016-07-01

    Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant. Although multiple adverse effects of PFOS have been demonstrated, whether PFOS can accelerate aging and affect animal longevity remains unknown. In Caenorhabditis elegans, we found that a 50 h exposure to 0.2-200 µM PFOS reduced lifespan in a concentration dependent manner. In transgenic nematodes, lifespans are affected by mutations of daf-16, daf-2 or age-1 genes, which are related to the Insulin/IGF-1 Signaling pathway (IIS). PFOS exposure caused an additional reduction in average lifespan in daf-2(e1370) and daf-16b(KO) nematodes. In contrast, daf-16(mu86) nematodes showed no additional reduction with PFOS exposure and age-1(hx546) mutants did not exhibit a reduction in lifespan with PFOS exposure, compared with wildtype nematodes. Overall, our findings demonstrate that PFOS exposure accelerates aging and shortens longevity of animals. The PFOS-induced effect may involve genes of the IIS pathway, particularly daf-16 and age-1. PMID:27095033

  2. Comparative study on adsorption of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) by different adsorbents in water.

    PubMed

    Yao, Yuan; Volchek, Konstantin; Brown, Carl E; Robinson, Adam; Obal, Terry

    2014-01-01

    Perfluorinated compounds (PFCs) are emerging environmental pollutants. Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are the two primary PFC contaminants that are widely found in water, particularly in groundwater. This study compared the adsorption behaviors of PFOS and PFOA on several commercially available adsorbents in water. The tested adsorbents include granular activated carbon (GAC: Filtrasorb 400), powdered activated carbon, multi-walled carbon nanotube (MCN), double-walled carbon nanotube, anion-exchange resin (AER: IRA67), non-ion-exchange polymer, alumina, and silica. The study demonstrated that adsorption is an effective technique for the removal of PFOS/PFOA from aqueous solutions. The kinetic tests showed that the adsorption onto AER reaches equilibrium rapidly (2 h), while it takes approximately 4 and 24 h to reach equilibrium for MCN and GAC, respectively. In terms of adsorption capacity, AER and GAC were identified as the most effective adsorbents to remove PFOS/PFOA from water. Furthermore, MCN, AER, and GAC proved to have high PFOS/PFOA removal efficiencies (≥98%). AER (IRA67) and GAC (Filtrasorb 400) were thus identified as the most promising adsorbents for treating PFOS/PFOA-contaminated groundwater at mg L(-1) level based on their equilibrium times, adsorption capacities, removal efficiencies, and associated costs. PMID:25521134

  3. Bioinformatic Characterization of the 4-Toluene Sulfonate Uptake Permease (TSUP) Family of Transmembrane Proteins

    PubMed Central

    Shlykov, Maksim A.; Zheng, Wei Hao; Chen, Jonathan S.; Saier, Milton H.

    2012-01-01

    The ubiquitous sequence diverse 4-Toluene Sulfonate Uptake Permease (TSUP) family contains few characterized members and is believed to catalyze the transport of several sulfur-based compounds. Prokaryotic members of the TSUP family outnumber the eukaryotic members substantially, and in prokaryotes, but not eukaryotes, extensive lateral gene transfer occurred during family evolution. Despite unequal representation, homologues from the three taxonomic domains of life share well-conserved motifs. We show that the prototypical eight TMS topology arose from an intragenic duplication of a four TMS unit. Possibly, a two TMS α-helical hairpin structure was the precursor of the 4 TMS repeat unit. Genome context analyses confirmed the proposal of a sulfur-based compound transport role for many TSUP homologues, but functional outliers appear to be prevalent as well. Preliminary results suggest that the TSUP family is a member of a large novel superfamily that includes rhodopsins, integral membrane chaperone proteins, transmembrane electron flow carriers and several transporter families. All of these proteins probably arose via the same pathway: 2 → 4 → 8 TMSs followed by loss of a TMS either at the N- or C-terminus, depending on the family, to give the more frequent 7 TMS topology. PMID:22192777

  4. Counterion Dynamics in Polyester-Sulfonate Ionomers with Ionic Liquid Counterions

    SciTech Connect

    Tudryn, Gregory J.; Liu, Wenjuan; Wang, Shih-Wa; Colby, Ralph H.

    2012-04-02

    Conventional sodium cations (Na{sup +}) in sulfonated polyester ionomers were replaced with ammonium-based ionic liquid counterions. Counterion dynamics were measured by dielectric spectroscopy and linear viscoelastic response via oscillatory shear. Ion exchange from sodium counterions to ionic liquid counterions such as tetramethylammonium and tetrabutylammonium showed an order of 10{sup 4} increase in conductivity compared with sodium counterions, primarily attributed to weaker ionic interactions that lower the glass transition temperature. Electrode polarization was used in conjunction with the 1953 Macdonald model to determine the number density of conducting counterions and their mobility. Conductivity and mobility exhibit Vogel-Fulcher-Tammann (VFT) temperature dependences and both increased with counterion size. Conducting counterion concentrations showed Arrhenius temperature dependences, with activation energy reduced as counterion size increased. When ether-oxygen was incorporated into the mobile cation structure, self-solvating ability notably increased the conducting ion concentration. Weakened ion pairing interactions prove favorable for fundamental design of single-ion conductors for actuators, as ionic liquid counterions can provide both larger and faster strains, required by such electro-active devices.

  5. Aqueous stability and mobility of C₆₀ complexed by sodium dodecyl benzene sulfonate surfactant.

    PubMed

    Peng, Xianjia; Yuan, Yue; Wang, Hongyu; Liang, Chuan

    2016-04-01

    Surfactant complexation may have significant effects on the environmental behavior of nano-particles. In order to understand the ecological exposure of nano-materials, it is important to determine the stability and mobility of surfactant-complexed nano-materials in aqueous systems. In this study, the aggregation and transport of C60 complexed by the surfactant sodium dodecyl benzene sulfonate (SDBS) were investigated. It was found that SDBS-complexed C60 had a ζ-potential of -49.5 mV under near-neutral pH conditions and remained stable during an aging period of 15 days. It had a critical coagulation concentration of 550 mmol/L for NaCl, which was higher than common natural colloids and many kinds of raw nano-materials, and was comparable to those of many kinds of surface-modified nano-materials. SDBS enhanced the stability of C60 colloid; however, at the same time, it also enhanced the colloidal particle aggregation rate. Much higher mobility was found for SDBS-complexed C60 than C60 colloid. Increase in ionic strength, Ca(2+) concentration or Al(3+) concentration decreased the mobility. In general, SDBS-complexed C60 had high stability and mobility. PMID:27090698

  6. Fate of linear alkylbenzene sulfonate in agricultural soil columns during inflow of surfactant pulses

    NASA Astrophysics Data System (ADS)

    Boluda-Botella, N.; León, V. M.; Cases, V.; Gomis, V.; Prats, D.

    2010-12-01

    The transport and reaction processes of linear alkylbenzene sulfonate (LAS) were characterised in columns of agricultural soil with a constant inflow of irrigation water. A pulse input of commercial LAS was performed with different mixtures of soil and sea sand (0/100%, 25/75% and 50/50%) and a continuous water flow of approximately 0.5 mL/min. LAS homologue retention was favoured at a higher soil rate, due mainly to higher clay and organic matter contents. C 10LAS and C 11LAS were less retained in soil columns, and were eluted faster and in higher proportion through soil columns than other homologues. C 12LAS and C 13LAS showed stronger interactions with soil due to their higher sorption capacity, and a lower proportion was eluted than the lightest homologues. In general, sorption of LAS was reversible and significant fractions were desorbed when the LAS input ceased and they were transported to deeper layers in the soil column, especially for short-chain homologues. Longer LAS homologues were eluted from soil columns, but required an elution of >10 pore-volumes. When there was biodegradation in the soil column, >25% of LAS could be removed, reducing percolation to deeper layers.

  7. Highly efficient sulfonated polybenzimidazole as a proton exchange membrane for microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Singha, Shuvra; Jana, Tushar; Modestra, J. Annie; Naresh Kumar, A.; Mohan, S. Venkata

    2016-06-01

    Although microbial fuel cells (MFCs) represent a promising bio-energy technology with a dual advantage (i.e., electricity production and waste-water treatment), their low power densities and high installation costs are major impediments. To address these bottlenecks and replace highly expensive Nafion, which is a proton exchange membrane (PEM), the current study focuses for the first time on membranes made from an easily synthesizable and more economical oxy-polybenzimidazole (OPBI) and its sulfonated analogue (S-OPBI) as alternate PEMs in single-chambered MFCs. The S-OPBI membrane exhibits better properties, with high water uptake, ion exchange capacity (IEC) and proton conductivity and a comparatively smaller degree of swelling compared to Nafion. The membrane morphology is characterized by atomic force microscopy, and the bright and dark regions of the S-OPBI membrane reveals the formation of ionic domains in the matrix, forming continuous water nanochannels when doped with water. These water-filled nanochannels are responsible for faster proton conduction in S-OPBI than in Nafion; therefore, the power output in the MFC with S-OPBI as the PEM is higher than in other MFCs. The open circuit voltage (460 mV), current generation (2.27 mA) and power density profile (110 mW/m2) as a function of time, as well as the polarization curves, exhibits higher current and power density (87.8 mW/m2) with S-OPBI compared to Nafion as the PEM.

  8. Determination and occurrence of secondary alkane sulfonates (SAS) in aquatic environments.

    PubMed

    Baena-Nogueras, Rosa María; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2013-05-01

    A new methodology has been developed for the determination of secondary alkane sulfonates (SAS), an anionic surfactant, in environmental matrices. Sediment and sludge samples were extracted using pressurized liquid extraction and sonication, whereas wastewater and surface water samples were processed using solid-phase extraction. Extraction recoveries were acceptable for both aqueous (78-120%) and solid samples (83-100%). Determination of SAS was carried out by high or ultra performance liquid chromatography - mass spectrometry using ion trap and time-of-flight detectors. The methodology was applied to samples from Guadalete River (SW Spain), where SAS concentrations below 1 μg L(-1) were measured in surface water, and from 72 to 9737 μg kg(-1) in sediments. Differential partitioning was observed for SAS homologues as those having a longer hydrocarbon chain which preferentially sorbed onto particulate matter. A preliminary environmental risk assessment also showed that SAS measured levels were not harmful to the aquatic community in the sampling area. PMID:23421983

  9. Insights into perfluorooctane sulfonate photodegradation in a catalyst-free aqueous solution

    NASA Astrophysics Data System (ADS)

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K. S.; Yu, Han-Qing

    2015-03-01

    Photodegradation in the absence of externally added chemicals could be an attractive solution for the removal of perfluorooctane sulfonate (PFOS) in aqueous environment, but the low decomposition rate presents a severe challenge and the underlying mechanisms are unclear. In this study, we demonstrated that PFOS could be effectively degraded in a catalyst-free aqueous solution via a reduction route. Under appropriate pH and temperature conditions, a rapid PFOS photodegradation, with a pseudo-first-order decomposition rate constant of 0.91 h-1, was achieved. In addition, hydrated electrons were considered to be the major photo-generated reductive species responsible for PFOS photodegradation in this system. Its production and reduction ability could be significantly affected by the environmental conditions such as pH, temperature and presence of oxidative species. This study gives insights into the PFOS photodegradation process and may provide useful information for developing catalyst-free photodegradation systems for decomposing PFOS and other persistent water contaminants.

  10. Insights into perfluorooctane sulfonate photodegradation in a catalyst-free aqueous solution

    PubMed Central

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K. S.; Yu, Han-Qing

    2015-01-01

    Photodegradation in the absence of externally added chemicals could be an attractive solution for the removal of perfluorooctane sulfonate (PFOS) in aqueous environment, but the low decomposition rate presents a severe challenge and the underlying mechanisms are unclear. In this study, we demonstrated that PFOS could be effectively degraded in a catalyst-free aqueous solution via a reduction route. Under appropriate pH and temperature conditions, a rapid PFOS photodegradation, with a pseudo-first-order decomposition rate constant of 0.91 h−1, was achieved. In addition, hydrated electrons were considered to be the major photo-generated reductive species responsible for PFOS photodegradation in this system. Its production and reduction ability could be significantly affected by the environmental conditions such as pH, temperature and presence of oxidative species. This study gives insights into the PFOS photodegradation process and may provide useful information for developing catalyst-free photodegradation systems for decomposing PFOS and other persistent water contaminants. PMID:25879866

  11. Sulfonated aluminum phthalocyanines for two-photon photodynamic cancer therapy: the effect of the excitation wavelength

    NASA Astrophysics Data System (ADS)

    Wang, J.; Li, W.; Yu, H. B.; Cheung, N. H.; Chen, J. Y.

    2014-03-01

    Sulfonated aluminum phthalocyanine (AlPcS) is a well-studied photosensitizer which has been widely used in research and in clinical applications of the photodynamic therapy of cancers. Conventionally, one-photon excitation was used, but it was unknown whether two-photon excitation of AlPcS was equally effective. In this study, the two-photon absorption cross sections of AlPcS at near infrared wavelengths were deduced from femtosecond (fs) laser-induced fluorescence. We found that the two-photon absorption cross section of AlPcS was strongly dependent on the excitation wavelength. It was about 19 GM when excited at 800 nm, but grew to 855 GM when excited at 750 nm. The 750 nm fs-laser-induced fluorescence images of AlPcS in human nasopharyngeal carcinoma cells were clearly visible while the corresponding images were very dim when excited at 800 nm. Singlet oxygen production was 13 times higher when excited at 750 nm relative to 800 nm. Our subsequent in vitro experiments showed that 750 nm two-photon excitation with an unfocused fs laser beam damaged cancer cells in a light-dose-dependent manner typical of photodynamic therapy (PDT). The killing at 750 nm was about 9-10 times more efficient than at 800 nm. These results demonstrated for the first time that AlPcS has good potential for two-photon PDT of cancers.

  12. Electrochemical investigation of methyl parathion at gold-sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode.

    PubMed

    Li, Chunya; Wang, Zhengguo; Zhan, Guoqin

    2011-01-01

    A gold/sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode (nano-Au/SDBS/GCE) was electrochemically fabricated with a constant potential at -0.4V. The obtained nano-Au/SDBS/GCE was characterized with scanning electronic microscopy, X-ray photoelectron spectroscopy and electrochemical techniques. Electrochemical behaviors of methyl parathion at the nano-Au/SDBS/GCE were thoroughly investigated. Compared to the unmodified electrode, the peak current obviously increased and the oxidation peak potential negatively shifted. These changes indicated that the composite nanoparticles possess good electrocatalytic performance on the electrochemical reaction of methyl parathion. Experimental parameters such as deposition time, pH value and accumulation conditions were optimized. Under optimum conditions, the peak current corresponding to the oxidation of the hydroxylamine group was found in a good linear relationship with the methyl parathion concentration. In addition, a calibration curve with excellent linearity was obtained in the concentration range from 5.0×10(-7)molL(-1) to 1.0×10(-4)molL(-1) with an estimated detection limit of 8.6×10(-8)molL(-1) (S/N=3). The successful determination of methyl parathion in real samples demonstrated the usefulness and potential applications of this method. PMID:20832258

  13. Fate of the Benzene Ring of Linear Alkylbenzene Sulfonate in Natural Waters

    PubMed Central

    Larson, R. J.; Payne, A. G.

    1981-01-01

    The biodegradability of linear alkylbenzene sulfonate (LAS) was studied in water samples collected from a receiving stream at locations above and below the discharge of a municipal wastewater treatment plant. Rates of primary biodegradation were determined for a commercial LAS mixture by a modified methylene blue-active substance method. Rates of LAS ultimate degradation were determined by radiochemical methods, using a C12 LAS homolog uniformly labeled with 14C in the benzene ring. The C12 LAS was tested at low concentrations (50 and 500 μg/liter) comparable to those existing in the receiving stream. Loss of methylene blue-active substance response over time occurred rapidly in water samples containing sediment collected from below the treatment plant, with an estimated half-life for LAS of 0.23 days. Evolution of 14CO2 during mineralization of the benzene ring occurred rapidly in the same samples, with a half-life for the benzene ring of 0.73 day. Mineralization of the benezene ring was also observed in river water containing no sediments and in river water and sediment samples collected from above the treatment plant. However, the rate of degradation was reduced in these cases, with half-lives for ring carbon ranging from 1.4 to 14 days. Although LAS degradation was enhanced in the presence of sediments, adsorption of LAS to the clay-silt fraction of river sediments was low, and most of the radioactivity was bound to biomass. PMID:16345731

  14. Removal of textile dyes and metallic ions using polyelectrolytes and macroelectrolytes containing sulfonic acid groups.

    PubMed

    Caldera Villalobos, M; Peláez Cid, A A; Herrera González, Ana M

    2016-07-15

    This work reports the removal of textile dyes and metallic ions by means of adsorption and coagulation-flocculation using two polyelectrolytes and two macroelectrolytes containing sulfonic acid groups. The adsorption of textile dyes was studied in aqueous solutions containing cationic dyes and in wastewater containing a vat dye. Also, removal of vat and naphthol dyes was studied using the process of coagulation-flocculation. The results show these materials possess elevated adsorption capacity, and they accomplished removal rates above 97% in aqueous solutions. The removal of the vat dye improved the quality of the wastewater notably, and an uncolored effluent was obtained at the end of the treatment. The treatment using adsorption decreased the values for coloration, conductivity, suspended solids, and pH. The removal of vat and naphthol dyes by means of coagulation-flocculation was studied as well, and removal rates of 90% were obtained. The polyelectrolytes and macroelectrolytes also proved effective in the adsorption of metallic ions in wastewater. The treatment using adsorption accomplished high removal rates of metallic ions, and it showed greater selectivity towards Cu(2+), Fe(3+) and Pb(2+). A decrease in the content of solids as well as the values for COD and conductivity was observed in the wastewater as well. The analyses of FT-IR indicated that cationic dyes and metallic ions were chemisorbed by means of ionic exchange. PMID:27082258

  15. Protein quantification by MALDI-selected reaction monitoring mass spectrometry using sulfonate derivatized peptides.

    PubMed

    Lesur, Antoine; Varesio, Emmanuel; Hopfgartner, Gérard

    2010-06-15

    The feasibility of protein absolute quantification with matrix-assisted laser desorption/ionization (MALDI) using the selected reaction monitoring (SRM) acquisition mode on a triple quadrupole linear ion trap mass spectrometer (QqQ(LIT)) equipped with a high-frequency laser is demonstrated. A therapeutic human monoclonal antibody (mAb) was used as a model protein, and four tryptic peptides generated by fast tryptic digestion were selected as quantification surrogates. MALDI produces mostly singly charged peptides which hardly fragment under low-energy collision-induced dissociation (CID), and therefore the benefits of using 4-sulfophenyl isothiocyanate (SPITC) as a fragmentation enhancer derivatization agent were evaluated. Despite a moderate impact on the sensitivity, the N-terminus sulfonated peptides generate nearly complete y-ion ladders when native peptides produce few fragments. This aspect provides an alternative SRM transition set for each peptide. As a consequence, SRM transitions selectivity can be tuned more easily for peptide quantitation in complex matrices when monitoring several SRM transitions. From a quantitative point of view, the signal response depending on mAb concentration was found to be linear over 2.5 orders of magnitude for the most sensitive peptide, allowing precise and accurate measurement by MALDI-SRM/MS. PMID:20481516

  16. Perfluorooctane sulfonate exposure causes gonadal developmental toxicity in Caenorhabditis elegans through ROS-induced DNA damage.

    PubMed

    Guo, Xiaoying; Li, Qingqing; Shi, Jue; Shi, Liulin; Li, Buqing; Xu, An; Zhao, Guoping; Wu, Lijun

    2016-07-01

    Perfluorooctane sulfonate (PFOS), a common persistent organic pollutant, has been reported to show potential developmental toxicity in many animal studies. However, little was known about its effects on reproductive tissues, especially in the germ line. In the present study, Caenorhabditis elegans was used as an in vivo experimental model to study the developmental toxicity caused by PFOS exposure, especially in the gonads. Our results showed that PFOS exposure significantly retarded gonadal development, as shown by the increased number of worms that remained in the larval stages after hatched L1-stage larvae were exposed to PFOS for 72 h. Investigation of germ line proliferation following PFOS exposure showed that the number of total germ cells reduced in a dose-dependent manner when L1-stage larvae were exposed to 0-25.0 μM PFOS. PFOS exposure induced transient mitotic cell cycle arrest and apoptosis in the germ line. Quantification of DNA damage in proliferating germ cells and production of reactive oxygen species (ROS) showed that distinct foci of HUS-1:GFP and ROS significantly increased in the PFOS-treated groups, whereas the decrease in mitotic germ cell number and the enhanced apoptosis induced by PFOS exposure were effectively rescued upon addition of dimethyl sulfoxide (DMSO) and mannitol (MNT). These results suggested that ROS-induced DNA damage might play a pivotal role in the impairment of gonadal development indicated by the reduction in total germ cells, transient mitotic cell cycle arrest, and apoptosis. PMID:27108369

  17. Effect of linear alkylbenzene sulfonate (LAS) on human intestinal Caco-2 cells at non cytotoxic concentrations.

    PubMed

    Bradai, Mohamed; Han, Junkyu; Omri, Abdelfatteh El; Funamizu, Naoyuki; Sayadi, Sami; Isoda, Hiroko

    2016-08-01

    Linear alkylbenzene sulfonate (LAS) is a cytotoxic synthetic anionic surfactant widely present in the environment due to its large-scale production and intensive use in the detergency field. In this study, we investigated the effect of LAS (CAS No. 25155-30-0) at non cytotoxic concentrations on human intestinal Caco-2 cells using different in vitro bioassays. As results, LAS increased Caco-2 cell proliferation at concentrations ranging from 1 to 15 ppm, more significantly for shorter exposure time (24 h), confirmed using flow cytometry and trypan blue exclusion methods. Moreover, proteomics analysis revealed that this effect was associated with an over-expression of elongation factor 2 and dipeptidyl peptidase 3, and a down-regulation of 14-3-3 protein theta, confirmed at mRNA level using real-time PCR. These findings suggest that LAS at non cytotoxic concentrations, similar to those observed at wastewater treatment plants outlets, increases the growth rate of colon cancer cells, raising thereby its tumor promotion effect potential. PMID:25999174

  18. Vibrational spectra of β-lactams—III. potassium 2-azetidinone-1-sulfonate and its isotopic compounds

    NASA Astrophysics Data System (ADS)

    Hanai, Kazuhiko; Maki, Yoshifumi; Kuwae, Akio

    1993-07-01

    The IR and Raman spectra of potassium 2-azetidinone-1-sulfonate and its three deuterated and two 15N-substituted compounds have been recorded, and the observed bands have been assigned on the basis of the isotope effects and the normal coordinate analysis. Comparison of the force constants for the amide group among 2-azetidinone, 1-methyl-2-azetidinone and potassium 2-azetidinone-1-sulfonate indicates that there is a correlation between these constants and the ease of hydrolysis which was determined by NMR spectroscopy, depending on the amide resonance.

  19. Distribution of fluorescence decay times for 1-anilinonaphthalene-8-sulfonate in human oxyhemoglobin A1b solution

    NASA Astrophysics Data System (ADS)

    Drazdou, A. S.; Sobchuk, A. N.; Syakhovich, V. E.; Bokut, O. S.; Kvasyuk, E. I.; Bushuk, B. A.; Bokut, S. B.

    2012-07-01

    We have studied complex formation between molecules of the fluorescent probe 1-anilinonaphthalene-8-sulfonate (1,8-ANS) and the major form (A1) and a minor form (Ab) of hemoglobin. The contribution of the longlived component f3 to the kinetic curves for fluorescence decay in HbA1b solutions is 0.021-0.036, which indicates a dramatic decrease (compared with HbA1) in the accessibility of the central cavity of HbA1b for binding 1,8-ANS. Disappearance of the long-lived component f3 in the fluorescence decay kinetics of 1,8-ANS in HbA1b solutions in the presence of inositol hexaphosphate (IHP) suggests that the regulatory region of HbA1b is completely inaccessible for interaction both with the negatively charged molecules of the probe and with natural regulators of the transport function for this form of the heme protein.

  20. Facile synthesis of 4H-chromene derivatives via base-mediated annulation of ortho-hydroxychalcones and 2-bromoallyl sulfones

    PubMed Central

    Thadkapally, Srinivas; Kunjachan, Athira C

    2016-01-01

    Summary The cesium carbonate-mediated reaction of 2-bromoallyl sulfones and ortho-hydroxychalcones furnished 3-arylsulfonyl-4H-chromene derivatives in 58–67% yield (18 examples). 2-Bromoallyl sulfones functioned as synthetic surrogates for allenyl sulfones in the reaction. PMID:26877804

  1. A new oxovanadium(IV) complex containing an O,N-bidentate Schiff base ligand: Synthesis at ambient temperature, characterization, crystal structure and catalytic performance in selective oxidation of sulfides to sulfones using H2O2 under solvent-free conditions

    NASA Astrophysics Data System (ADS)

    Menati, Saeid; Rudbari, Hadi Amiri; Khorshidifard, Mahsa; Jalilian, Fariba

    2016-01-01

    A new bidentate ON Schiff base ligand, HL, was synthesized by simple condensation reaction of isopropylamine and salicylaldehyde. Then by reaction of HL and VO(acac)2 in the ratio of 2:1 at ambient temperature, a new oxovanadium(IV) Schiff base complex, VOL2, was synthesized. The Schiff base ligand and its oxovanadium(IV) complex were characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR and UV-visible spectroscopies. The crystal structure of oxovanadium(IV) complex, VOL2, was also determined by single crystal X-ray analysis. The vanadium center in this structure is coordinated to two bidentate Schiff base ligands with the two nitrogen and two phenolate oxygen atoms in equatorial positions and one oxo oxygen in the axial position to complete the distorted trigonal bipyramidal N2O3 coordination sphere. Catalytic performance of the VOL2 complex was studied in the selective oxidation of thioanisole with the green oxidant 35% aqueous H2O2 under solvent-free conditions and under organic solvents (EtOH, CHCl3, CH2Cl2, DMF, CH3CN, EtOAc) as a model. Due to better catalytic performance of the VOL2 complex under solvent-free conditions, this complex used for the oxidation of the different sulfides to the corresponding sulfones under solvent-free conditions. The use of hydrogen peroxide as oxidant and the absence of solvent makes these reactions interesting from environmental and economic points of view.

  2. Structure-guided design of a novel class of benzyl-sulfonate inhibitors for influenza virus neuraminidase

    PubMed Central

    Platis, Dimitris; Smith, Brian J.; Huyton, Trevor; Labrou, Nikolaos E.

    2006-01-01

    Influenza NA (neuraminidase) is an antiviral target of high pharmaceutical interest because of its essential role in cleaving sialic acid residues from cell surface glycoproteins and facilitating release of virions from infected cells. The present paper describes the use of structural information in the progressive design from a lead binding ion (a sulfate) to a potent submicromolor inhibitor (Ki 0.13 μM). Structural information derived from the X-ray structure of an NA complexed with several sulfate ions, in combination with results derived from affinity labelling and molecular modelling studies, was used to guide design of potent sulfonic acid-based inhibitors. These inhibitors are structural fragments of the polysulfonate triazine dye Cibacron Blue 3GA and represent novel lead scaffolds for designing non-carbohydrate inhibitors for influenza neuraminidases. PMID:16776653

  3. Pharmacokinetic profiles of perfluorobutane sulfonate and activation of hepatic genes in mice

    EPA Science Inventory

    Polyfluoroalkyl substances (PFAS) are organic chemicals with wide industrial and consumer uses. They are found ubiquitously at low levels in the environment and detectable in humans and wildlife. Perfluorobutane Sulfonate (PFBS) is a short-chained PFAS used to replace perfluorooc...

  4. SWELLING OF PEATS IN LIQUID METHYL, TETRAMETHYLENE AND PROPYL SULFOXIDES AND IN LIQUID PROPYL SULFONE

    EPA Science Inventory

    The interactions of methyl, tetramethylene, and propyl sulfoxides and propyl sulfone during sorption onto four de-waxed, acid-form peats have been studied by means of swelling measurements. The results for sulfoxides are displayed as het-eromolecular sorption isotherms, which plo...

  5. Camphorquinone-10-sulfonic acid and derivatives: convenient reagents for reversible modification of arginine residues

    SciTech Connect

    Pande, C.S.; Pelzig, M.; Glass, J.D.

    1980-02-01

    Camphorquinone-10-sulfonic acid hydrate was prepared by the action of selenous acid on camphor-10-sulfonic acid. Camphorquinone-10-sulfonylnorleucine was prepared either from the sulfonic acid via the sulfonyl chloride or by selenous acid oxidation of camphor-10-sulfonylnorleucine. These reagents are useful for specific, reversible modification of the guanidino groups of arginine residues. Camphorquinonsulfonic acid is a crystalline water-soluble reagent that is especially suitable for use with small arginine-containing molecules, because the sulfonic acid group of the reagent is a convenient handle for analytical and preparative separation of products. Camphorquinonesulfonylnorleucine is more useful for work with large polypeptides and proteins, because hydrolysates of modified proteins may be analyzed for norleucine to determine the extent of arginine modification. The adducts of the camphorquinone derivatives with the guanidino group are stable to 0.5 M hydroxylamine solutions at pH 7, the recommended conditions for cleavage of the corresponding cyclohexanedione adducts. At pH 8-9 the adducts of the camphorquinone derivatives with the guanidino group are cleaved by o-phenylenediamine. The modification and regeneration of arginine, of the dipeptide arginylaspartic acid, of ribonuclease S-peptide, and of soybean trypsin inhibitor are presented as demonstrations of the use of the reagents.The use of camphorquinonesulfonyl chloride to prepare polymers containing arginine-specific ligands is discussed.

  6. Adsorption behavior and mechanism of perfluorooctane sulfonate on nanosized inorganic oxides.

    PubMed

    Lu, Xinyu; Deng, Shubo; Wang, Bin; Huang, Jun; Wang, Yujue; Yu, Gang

    2016-07-15

    Adsorption of perfluorooctane sulfonate (PFOS) on manufactured nanoparticles (NPs) is critical for understanding their transport and fate in aquatic environments. In this study, the adsorption behavior of PFOS on nanosized Al2O3, Fe2O3, SiO2 and TiO2 was examined in terms of adsorption isotherms and influences of pH, ionic strength and heavy metallic cations. The nano-oxides had much higher adsorption capacities than bulk particles due to higher surface hydroxyl density. PFOS adsorption showed strong pH dependence due to different species of surface hydroxyl groups on nano-oxides. Besides electrostatic interaction, sulfonic group of PFOS possibly formed hydrogen bonds on the surface of nano-oxides. Because of the bridging effect in the co-adsorption process, the coexisting PFOS and heavy metallic cations greatly enhanced their adsorption onto the nano-oxides. Comparative adsorption of different perfluorinated sulfonates indicated the possible formation of bilayer PFOS adsorption on the nano-oxides, leading to the enhanced Cu(II) adsorption on the sulfonic groups of PFOS on the surfaces through electrostatic interaction. PMID:27127908

  7. Analysis of aromatic sulfonates in water by solid-phase extraction and capillary electrophoresis.

    PubMed

    Loos, R; Niessner, R

    1998-10-01

    The separation of 14 different aromatic sulfonates of environmental concern by capillary (zone) electrophoresis (CZE) is presented. A new off-line solid-phase extraction (SPE) enrichment procedure, that is compatible with CE analysis, was developed, using the styrene-divinylbenzene adsorbent LiChrolut EN. The combined method of SPE and CE allows the determination of aromatic sulfonates in water samples in the low microgram/l range. Separations are performed with a simple sodium borate buffer at pH 9.3. Analytes are detected by UV absorbance and fluorescence emission with a Xe-lamp excitation source, and both principles are compared. The recoveries for most of the sulfonates are > 70% for the extraction from spiked tap and river water. The average method precision is < 20% for replicate analyses. Very hydrophilic sulfonates cannot be extracted by this method. The detection limit of the combined method of SPE enrichment and CE analysis is approximately 0.1 microgram/l for 200-ml water samples. The performance of the method was checked with the analysis of river and contaminated seepage water. PMID:9809447

  8. EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON THYROID HORMONE STATUS IN ADULT AND NEONATAL RATS

    EPA Science Inventory

    EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON THYROID HORMONE STATUS IN ADULT AND NEONATAL RATS. M.N. Logan1, J.R. Thibodeaux2, R.G. Hanson2, C. Lau2. 1North Carolina Central University, Durham, NC, 2Reprod. Tox. Div. NHEERL, US EPA, Research Triangle Park, NC.

    Perfluor...

  9. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  10. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  11. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  12. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  13. 40 CFR 721.9597 - Salt of a substituted sulfonated aryl azo compound (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... azo compound (generic). 721.9597 Section 721.9597 Protection of Environment ENVIRONMENTAL PROTECTION... compound (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as salt of a substituted sulfonated aryl azo compound (PMN P-00-0094)...

  14. Distribution and excretion of perfluorooctane sulfonate (PFOS) in beef cattle (Bos taurus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS), a perfluoroalkyl surfactant used in many industrial products, is present in industrial wastes and in wastewater treatment plant biosolids. Biosolids are commonly applied to pastures and crops used for animal feed; consequently, PFOS may accumulate in the edible tis...

  15. Fipronil toxicity in northern bobwhite quail Colinus virginianus: reduced feeding behaviour and sulfone metabolite formation.

    PubMed

    Kitulagodage, Malsha; Isanhart, John; Buttemer, William A; Hooper, Michael J; Astheimer, Lee B

    2011-04-01

    Fipronil is a phenyl pyrazole insecticide registered for agricultural use in many countries. Avian exposure to fipronil occurs mainly by ingesting contaminated insects or seeds. There is little information regarding the toxicological effects of fipronil in avian species and even less research documenting avian behavioural responses to fipronil ingestion. We examined the effects of a single oral dose of fipronil in northern bobwhite quail, the most fipronil-sensitive species tested to date, in respect to signs of intoxication and the metabolic fate of fipronil. Fipronil-treated birds did not eat or drink following pesticide administration, and as a result lost a significant amount of body mass. Treated birds also appeared withdrawn and did not respond to disturbance within the first hour after treatment. Identifiable signs of fipronil toxicity were not observed until at least 2d after treatment. Chemical analyses indicated a difference between fipronil and fipronil-sulfone residue distribution and bioaccumulation, with significantly higher (30- to 1000-fold) tissue concentrations of the sulfone detected at all time points from 8 to 96 h post-dose in brain, liver and adipose tissues. Tissue sulfone concentrations increased significantly in fipronil-treated birds, peaking at 72 h post-dose. Body mass decreased at all time points in dosed birds. The coincidence of the particular intoxication symptoms with the time course of rise in brain sulfone levels after fipronil dosing gives insight into possible mechanisms of toxicity in this highly sensitive species. PMID:21227481

  16. Chiral separation of metolachlor ethane sulfonic acid as a groundwater dating tool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have studied the hydrologic fate of metolachlor and its two predominant metabolites, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid, in groundwater and base flows of streams for several years. These two metabolites are excellent markers for groundwater processes related to...

  17. Using chiral identification of metolachlor ethane sulfonic acid as a groundwater dating tool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have studied the hydrologic fate of metolachlor and its two predominant metabolites, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid, in groundwater and base flows of streams for several years. These two metabolites are excellent markers for groundwater processes related to...

  18. EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON MATERNAL AND DEVELOPMENTAL THYROID STATUS IN THE RAT

    EPA Science Inventory

    EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON MATERNAL AND DEVELOPMENTAL THYROID STATUS IN THE RAT. JR Thibodeaux1, R Hanson1, B Grey1, JM Rogers1, ME Stanton2, and C Lau1. 1Reproductive Toxicology Division; 2Neurotoxicology Division, NHEERL, ORD, US EPA, Research Triangle P...

  19. Exposure to perfluorooctane sulfonate during pregnancy in rat and mouse. II: postnatal evaluation

    EPA Science Inventory

    The postnatal effects of in utero exposure to perfluorooctane sulfonate (PFOS, C8F17SO3-) were evaluated in the rat and mouse. Pregnant Sprague-Dawley rats were given 1, 2, 3, 5, or 10 mg/kg PFOS daily by gavage from gestation day (GD) 2 to GD 21; pregnant CD-1 mice were treated ...

  20. Sulfonated graphene oxide as effective catalyst for conversion of 5-(hydroxymethyl)-2-furfural into biofuels.

    PubMed

    Antunes, Margarida M; Russo, Patrícia A; Wiper, Paul V; Veiga, Jacinto M; Pillinger, Martyn; Mafra, Luís; Evtuguin, Dmitry V; Pinna, Nicola; Valente, Anabela A

    2014-03-01

    The acid-catalyzed reaction of 5-(hydroxymethyl)-2-furfural with ethanol is a promising route to produce biofuels or fuel additives within the carbohydrate platform; specifically, this reaction may give 5-ethoxymethylfurfural, 5-(ethoxymethyl)furfural diethylacetal, and/or ethyl levulinate (bioEs). It is shown that sulfonated, partially reduced graphene oxide (S-RGO) exhibits a more superior catalytic performance for the production of bioEs than several other acid catalysts, which include sulfonated carbons and the commercial acid resin Amberlyst-15, which has a much higher sulfonic acid content and stronger acidity. This was attributed to the cooperative effects of the sulfonic acid groups and other types of acid sites (e.g., carboxylic acids), and to the enhanced accessibility to the active sites as a result of the 2D structure. Moreover, the acidic functionalities bonded to the S-RGO surface were more stable under the catalytic reaction conditions than those of the other solids tested, which allowed its efficient reuse. PMID:24497470

  1. FT-IR SOLUTION SPECTRA OF PROPYL SULFIDE, PROPYL SULFOXIDE, AND PROPYL SULFONE

    EPA Science Inventory

    FT-IR spectra were obtained of 0.5% volumetric solutions of propyl sulfide, propyl sulfoxide, and propyl sulfone in hexane, CCl4, CS2, and CHCl3 to assist in the assignment of FT-IR-PAS spectra of propyl sulfoxide sorbed within the structure of several peats and onto cellulose. T...

  2. Sulfonated mesoporous silica-carbon composites and their use as solid acid catalysts

    NASA Astrophysics Data System (ADS)

    Valle-Vigón, Patricia; Sevilla, Marta; Fuertes, Antonio B.

    2012-11-01

    The synthesis of highly functionalized porous silica-carbon composites made up of sulfonic groups attached to a carbon layer coating the pores of three types of mesostructured silica (i.e. SBA-15, KIT-6 and mesocellular silica) is presented. The synthesis procedure involves the following steps: (a) removal of the surfactant, (b) impregnation of the silica pores with a carbon precursor, (c) carbonization and (d) sulfonation. The resulting silica-carbon composites contain ˜30 wt % of carbonaceous matter with a high density of acidic groups attached to the deposited carbon (i.e.sbnd SO3H, sbnd COOH and sbnd OH). The structural characteristics of the parent silica are retained in the composite materials, which exhibit a high surface area, a large pore volume and a well-ordered porosity made up uniform mesopores. The high density of the sulfonic groups in combination with the mesoporous structure of the composites ensures that a large number of active sites are easily accessible to reactants. These sulfonated silica-carbon composites behave as eco-friendly, active, selective, water tolerant and recyclable solid acids. In this study we demonstrate the usefulness of these composites as solid acid catalysts for the esterification of maleic anhydride, succinic acid and oleic acid with ethanol. These composites exhibit a superior intrinsic catalytic activity to other commercial solid acids such as Amberlyst-15.

  3. FTIR SOLUTION SPECTRA OF PROPYL SULFIDE, PROPYL SULFOXIDE, AND PROPYL SULFONE

    EPA Science Inventory

    FTIR spectra were obtained of 0.5% volumetric solutions of propyl sulfide, propyl sulfoxide and propyl sulfone in hexane, CC14, CS2, and CHCl3 to assist in the assignment of FTIR-PAS spectra of propyl sulfoxide sorbed within the structure of several peats and onto cellulose. he C...

  4. GENE PROFILING IN WILD-TYPE AND PPARα-NULL MICE EXPOSED TO PERFLUOROOCTANE SULFONATE

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS), a perfluoroalkyl acid (PFAA), is a persistent environmental contaminant found in the tissues of humans and wildlife. Over the last decade, health concerns have been raised, in part, because of the long half-life of PFOS and other PFAAs in humans,...

  5. Synthesis and biological evaluation of heteroanalogues of kotalanol and de-O-sulfonated kotalanol.

    PubMed

    Mohan, Sankar; Jayakanthan, Kumarasamy; Nasi, Ravindranath; Kuntz, Douglas A; Rose, David R; Pinto, B Mario

    2010-03-01

    The synthesis of nitrogen and selenium analogues of kotalanol and de-O-sulfonated kotalanol, naturally occurring sulfonium-ion glucosidase inhibitors isolated from Salacia reticulata, and their evaluation as glucosidase inhibitors against the N-terminal catalytic domain of human maltase glucoamylase (ntMGAM) are described. PMID:20143790

  6. Perfluoroctane sulfonate-induced changes in fetal rat liver gene expression

    EPA Science Inventory

    In utero exposure of rats to perfluorooctane sulfonate (PFOS, C8F17SO3), a widely disseminated product of the surfactant and coating industries, is associated with residual hepatoxic complications in the surviving offspring. This hepatocellular hypertrophy resembles that observe...

  7. Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes

    DOEpatents

    Fujimoto, Cy H.; Hibbs, Michael; Ambrosini, Andrea

    2012-02-07

    Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.

  8. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  9. 40 CFR 417.90 - Applicability; description of the oleum sulfonation and sulfation subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Applicability; description of the oleum sulfonation and sulfation subcategory. 417.90 Section 417.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  10. 40 CFR 417.90 - Applicability; description of the oleum sulfonation and sulfation subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the oleum sulfonation and sulfation subcategory. 417.90 Section 417.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  11. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  12. 40 CFR 417.90 - Applicability; description of the oleum sulfonation and sulfation subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Applicability; description of the oleum sulfonation and sulfation subcategory. 417.90 Section 417.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  13. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  14. 40 CFR 417.90 - Applicability; description of the oleum sulfonation and sulfation subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Applicability; description of the oleum sulfonation and sulfation subcategory. 417.90 Section 417.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  15. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  16. 40 CFR 417.90 - Applicability; description of the oleum sulfonation and sulfation subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the oleum sulfonation and sulfation subcategory. 417.90 Section 417.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT...

  17. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  18. MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE MOUSE

    EPA Science Inventory

    MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE MOUSE. J.R. Thibodeaux1, R.G. Hanson1, B.E. Grey1, B.D. Barbee1, J.H. Richards2, J.L. Butenhoff3, J.M. Rogers1, C. Lau1. 1Reprod. Tox. Div., 2Exp. Tox. Div., NHEERL, ORD, US EPA, Research Triangle Pa...

  19. MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCATANE SULFONATE (PFOS) IN THE RAT

    EPA Science Inventory

    MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE RAT. C. Lau1, J.M. Rogers1, J.R. Thibodeaux1, R.G. Hanson1, B.E. Grey1, B.D. Barbee1, J.H. Richards2, J.L. Butenoff3. 1Reprod. Tox. Div., 2Exp. Tox. Div., NHEERL, USEPA, Research Triangle Park, NC, 3...

  20. ENVIRONMENTAL APPLICATIONS OF THERMOSPRAY LCMS: QUALITATIVE ANALYSIS OF SULFONATED AZO DYES

    EPA Science Inventory

    Thermospray mass spectra (TSMS) has been used to obtain mass spectra of several di- and tetra- sulfonated azo dyes. Commercial dye preparations were dissolved in various mobile phases and injected into the TSMS system. Mobile phases investigated included pure water and varying co...